THE day on which my story opens—June 6, 2012—was marked in advance as the date of a transit of Venus across the disk of the sun. It will have a foremost place in the minds of future generations of school children as the date on which the first expedition of colonists from Earth landed on the neighboring planet.

Although a broken leg prevented me from being a member of that band of brave men, my later destiny was closely linked with their amazing adventures on Venus, and it is their story, in so far as I was connected with it, that I shall set down here to the best of my ability.

An introductory word about myself is necessary. The first space trips—those venturesome leaps to the moon—were made when I was a schoolboy. They fired the imagination of the world, and I was only one of the millions of boys who resolved to devote their lives to the exploration of space. Partly because I was more persistent than some, and partly because I was more fortunate, I was able to follow the line of my ambition. What will always stand out as the biggest day in my life was that on which, my theoretical training completed, I hopped off on my first space trip, in which I circled the moon. Prior to that time Robert E. Jones and Matthew Eddy had already made their epochal trip to Venus, and I looked upon my first space voyage as merely further training that would equip me for similar exploits.

When it was decided to send a large expedition to remain at least two years on Venus and investigate the deposits of radium-bearing pitchblende found by Jones and Eddy in their brief stay, I was accepted as a member of the party, and took part in the preparations. My high expectations were rudely dashed when, a month before the start, my run of good fortune was ended by the accident in which my leg was broken. That, of course, disposed of my hope of accompanying the expedition. Dr. Franklin Sanders, chairman of the Commission for Venus, offered me the post of wireless operator, which I gladly accepted. My duties were to aid in the installation of the station which would be used to communicate with the men on Venus, and, after communications were established, to keep one of the three eight-hour "watches" at the receiving set. At the same time I was to aid in preparations for a second expedition to be sent out two years later when Venus would again be in inferior conjunction with Earth.

On June 6, 2012, then, I left an assistant in the wireless room and went to the roof of the building in Washington, D. C.. furnished the Commission by the North American Continental Government. It is unnecessary for me to describe the transit of Venus across the sun's disk, for all of my readers must have witnessed the phenomen either in 2012 or 2004. I do wish, however, to record a conversation with Dr. sanders, because it will show our expectant attitude on that day when the expedition, out 26 days, was scheduled to arrive on Venus. I was watching the sun, with the planet outlined against it, through a pair of binoculars when Dr. Sanders approached me.

"If all has gone well," he said, "we should be in communication with them in a few days, now."

"I'm sure all has gone as planned, sir," I replied. "Nothing could go wrong with Commander Jones in charge."

"He is a wonderful leader," Dr. Sanders agreed. "I share your confidence in him. Nevertheless interplanetary travel is still fraught with many perils, as you know better than I. It is a long and dangerous voyage, but I trust it has been accomplished successfully."

"Their adventures will Only have begun when they land," I said. "They will still have to cope with all the dangers of a world such as ours must have been a' million years ago."

"And you would give your right eye to be with them," Dr. Sanders smiled. "Don't worry, Starrett, you'll join them at the first opportunity."

I SMILED, rather wryly, I am afraid, for I knew that the "next opportunity would not come for almost two years. From that day Venus and Earth would steadily separate until, some ten months later, they would be on opposite sides of the sun and separated by more than 160,000,000 miles, instead of a mere 25,000,000 miles as at present. No trip between the two planets could be considered until Venus again approached inferior conjunction.

Dr. Sanders read my thoughts.

"Venus won't be civilized in two years, my boy," he said, "nor in two decades. I'm sure you will have your part in the work of civilizing it, and your share of adventure. It is no secret, of course, that the present plan is to establish a permanent colony on the planet. There must be untold resources to be developed. I can visualize the day when Venus will have a thriving population of men and women."

An almost religious light shone in his eyes as he continued.

"Beautiful cities will be planned and erected free from the blemishes that on Earth we have inherited from past ages of trial and error. Commerce will ply the seas of Venus and there will be a steady exchange of goods between the planets. Venus may come to be regarded as the 'promised land' for the inhabitants of Earth. In some future age when the earth receives less heat from the dying sun, mankind may desert its old home and move to the new world nearer the source of life."

He clapped me on the shoulder.

"These are glorious prospects that we have before us in the dawn of the 21st Century. Adventure such as no man ever dreamed of a few centuries ago! My boy, the great adventure is just beginning. I predict that you will have a big part in furthering it. So don't let your spirits be cast down now."

I do not remember what reply I made, except that I stammered my thanks for his kind words. His enthusiasm and vision were contagious, although there was nothing new to me in what he said. Later on, however, when I was back in the room which housed the interplanetary wireless set, my disappointment rose afresh. After all I had wished to be a pioneer, and it would not be the same going out with a second party two years later to find the ground broken, homes erected and a little community ready to receive us. Nothing could he done about it, however. I had missed my big chance through such a trivial thing as a fall and a broken leg.

The bone had practically healed by this time, but it was too late. The expedition had departed twenty-six days earlier, and, as we learned later, landed on Venus on that very day and near the time when the planet was seen from Earth in transit across the sun's face. I little guessed that day how fortunate it was for all concerned that I was not with them.

CHAPTER II.

Mystery on Venus.

IT was three days later before any word was received from Venus, the delay being explained by the necessity for the technicians of the expedition to assemble the wireless and getting it in working order. I still have copies of the messages received in the Washington headquarters, so that I am able to give their exact texts. They tell a dramatic story of mystery and suspense in a strange and unfriendly world.

Contact was established on June 9. I was on duty at the time and was reporting periodically to Dr. Sanders that no results had been obtained. The wavelength to be used was so low that there was no interference from Earth stations. I was tuning the set near the agreed point when I caught a faint signal. I perfected the adjustment and then waited. If it were indeed Venus calling, the signal would be repeated in exactly five minutes. Precisely at the end of that period, which I spent watching the second hand creep around the dial of my watch, I caught the signal again, much louder. It was the Venus station repeating the station call for Earth.

I tapped out the answer to show that communication had been established, and then sent for Dr. Sanders. It would be more than two minutes before the radio signal, traveling with the speed of light, would reach Venus, and an equal time before the reply could be heard.

Dr. Sanders entered the room, followed by others who had heard the good news. There were excited whispers, which I stilled with a motion of my hand. Although the message was taken down automatically by the receiving instruments, I was unwilling to risk the possibility of mechanical trouble and accordingly wrote the message down.

"Earth, attention! Earth, attention! Arrived three days ago. All O. K. We landed near mouth of Holmes River and have begun construction of permanent home on favorable site. Living in the ships pending completion of thatched roof huts. Party of hunters on first day surprised herd of sexons¹ and killed enough to supply us with meat for a week. Have caught several forms of river life in nets and Dr. Alexander is analyzing them. Potato trees are plentiful and the root, with sexon meat and bread, completes our diet until Dr. Alexander tells us what else we can eat.

1: An ostrich-like bird having six rudimentary legs, whence the name.

"Have divided party in two groups and alternate daily, one group exploring neighborhood and collecting specimens of vegetable and animal life while others cut and haul lumber. The wood of the potato tree is strong and light, and the rough sawed lumber has the quality of glowing faintly for several hours after sunset. Lizards of many types and all sizes are abundant, but apparently harmless. We hope to begin work on radium field in few weeks when camp is completed. Men all gathered to wait your reply. Send greetings to friends on Earth. Robert E. Jones."

Dr. Sanders quickly scribbled the answer, which I began sending within a few minutes after the completion of this message. In the meantime the news had been flashed to all parts of the world. Congratulatory messages from notables began arriving and were transmitted to the distant party. It was more than two hours later when we said good-bye for the day.

It is remarkable that from the first there was no difficulty in communicating with the party on Venus. It had been realized, of course, that communication could not be maintained during that part of the synodic revolutions of the two planets when they were at nearly opposite sides of the sun, and the most hoped for was that we could keep in touch with the distant party during the five or six months preceding and following inferior conjunction. Our experience proved beyond doubt that this was possible, although, because of circumstances which I shall soon relate, we actually maintained touch with Commander Jones and his party for only thirty days. The breaking of communications at the end of that time had nothing to do with radio conditions. If there had been anyone to operate the station on Venus the signals would have been received at the Washington station.

AT the first, however, Commander Jones could send a message from Venus in confidence that it would be received about two minutes later on Earth. A program was worked out by which we made contact with the party at noon (Washington time) every day. That was merely for convenience and regularity, as there was always some one on duty in the receiving room in the commission building to receive an emergency message if there were any occasion for one.

During the first week Commander Jones daily message told a story of regular progress in establishing a home under the tropical and primitive conditions of the new world. The messages might almost have come from a party in some still uncivilized section near the equator except for references to strange plants and animals similar to those which may have existed on Earth before the dawn of human life.

The first hint of what was to come was contained in a message received on June 17. It read:

"Something has happened that we are unable to understand. Dick Smith and James Fall disappeared yesterday afternoon when they were cutting down trees a short distance from the camp, and no trace of them has been found as yet. We have dropped everything else to look for them. No one can explain what may have happened to them. We have seen vensaurians large enough to carry a man, or even two, without much difficulty, but none was seen near the time the men disappeared, and no tracks were found in the neighborhood where they were working. The large species that we have seen appear to be herbivorous and have shown no signs of attacking us. What adds to the mystery is the fact that both men were armed, and would certainly have used their pistols if attacked. No shots were heard by others working nearby. We hope that they have merely strayed away and become lost, but we do not know what to fear. I have ordered a guard on the camp at all hours. We will continue our efforts to find Smith and Fall."

This message was a private one to Dr. Sanders, and he did not make it public, since to have done so would have served no useful purpose, but would have aroused futile fears among relatives and friends not only of the two men but of all those in the party.

Subsequent messages from Commander Jones informed those of us connected with the commission that no trace of the missing men had been found. The others, after a futile search, returned to the other work which it was necessary for them to do. The camp was completed and operations were begun on the radium mine.

On July 5th we received the following message from Commander Jones:

"I am forced to the conclusion that there is some intelligent and malevolent force at work against us. What its nature may be it is impossible to say, but on no other hypothesis can I explain the invasion of our camp last night.

"There was no outcry during the night, but when we awoke this morning we found that three men who had been on guard and three other men who slept in a hut near the edge of camp had disappeared. We found no sign of bloodshed nor of a struggle of any sort, which makes the occurrence absolutely incomprehensible.

"During the morning I decided to go up a short distance in one of the space ships to survey the land, and possibly to lead the missing men back to camp if they were free. It was then we made the discovery that the ships had been entered and our tanks of fuel mixture carried away. This, apparently, had been done at the same time the men were spirited away, for I am unable to believe they took the fuel and left the camp of their own accord.

"At any rate we are now stranded here, and apparently at the mercy of unseen foes. The morale of the forty-eight men remaining in the camp is unimpaired by this latest development. We are all determined to solve the mystery and find out what happened to our comrades.

"The loss of our fuel mixture is a serious blow, since it means that we are forced to remain where we are and will he unable to do any extensive exploring unless we recover the tanks. The camp will be put on a war basis until we determine the nature of the danger which threatens us."

This message was the last that was received from the expedition.

Later that afternoon I tried to make connection with the station on Venus to transmit a message from Dr. Sanders. I was unable to obtain a reply. Nor was there any word from the expedition the following day at the usual time.

CHAPTER III.

A Desperate Plan.

SEVERAL days later Dr. Sanders sent for me to come to his office. I could tell from his nervous manner as he bade me sit down that he had something of importance to say. He began abruptly:

"We have held several meetings of the Commission," he said, "to discuss the situation regarding the expedition now on Venus. While we can only guess at what may have happened to the party, the sudden breaking of communications following the mysterious disappearance of eight of the men and the raid on the camp, indicates that some disaster has overtaken them.

"What makes the matter more serious is the loss of their fuel mixture, without which they are unable to operate the space ships. That means that they cannot move from the spot where they landed, on the northern coast of Elysia, and if they are beset by foes in overwhelming force they are unable to escape to some other part of the planet. Of course the fact that the fuel mixture was singled out for theft indicates that their foes are intelligent beings of some sort. This is in absolute contradiction to the apparently well-established fact that nothing corresponding to human life exists on Venus, but we are forced to accept the fact as it stands.

"We have decided, in short, that aid must be sent to the party and especially that we must get a supply of fuel mixture to them.

"I don't think it is possible," I protested, when he paused. "Venus is rapidly separating from the Earth at present. A space ship which started out now would have to follow the planet through its orbit and could only gain on it slowly, possibly one or two hundred thousand miles a day.² At that rate. even if the ship could carry enough liquid air and fuel mixture for the long journey, it would not overtake the planet for almost a year."

2: The speed or Venus in its orbit is about 22 miles per second; that of the earth 18.5 miles per second. If an attempt were made to reach Venus directly, it would be like chasing after a fast-receding train.

"By all the accepted standards and theories that is correct," Dr. Sanders replied. "Such an attempt would of course be foredoomed to failure. Necessity, however, is the mother of invention, and a plan has been worked out for the Commission under which we believe a space ship setting out now can reach Venus within two months. If you will consider making the trip, I will explain the idea lo you. It is unnecessary for me to say that it will be hazardous in the extreme, or to point out that the lives of the 56 men who landed on Venus a month ago may be at stake. What do you say?"

"I am willing," I replied.

Dr. Sanders drew out a sheet of paper on which was drawn a system of circles and dotted lines, and which I immediately recognized as indicating the orbits of Earth and Venus around the sun. The sketch is reproduced here so that the reader can follow Dr. Sanders' explanation.

"The plan, as I have told you, is an extremely daring one," Dr. Sanders continued. "It, is nothing less than to launch a ship into space at the proper direction and at such a speed that it will circle the sun and return in time to meet the planet Venus, in its orbit.

"The plan is shown on this diagram. The letters 'E' and 'V' show the respective positions of Earth and Venus in their orbits at the time of the recent transit. The small circles on the orbits 'E' and 'V' show the positions in which the two planets will be on July 21, when all should he in readiness for the start of the trip."

Looking at the diagram I began to get a faint understanding of the plan, which was indeed a daring one.

"Our calculations show that in one of the small and speedy ships you would have to travel under power for about 36,000,000 miles along the course indicated," Dr. Sanders said. "Since the course lies approximately in the direction of the sun your speed would increase rapidly alter you passed the point where the sun's attraction equalled the earth's. After 36,000,000 miles your speed would be such that you could shut off your power and leave the ship to sweep around the sun just as the comet does, and in the path indicated. At the end of 4-5 days the ship would have whipped comet-like around the sun and re-turned to the orbit of Venus, and the planet would have moved forward to the same point V2. Thus your trip would require less than twice the time taken by Commander Jones and his party, although you would cover almost 200,000,000 miles in reaching the planet."

"THE course lies very close to the sun," I said, after studying the diagram for a moment.

"Yes, you would pass within 20,000,000 miles of the sun," Dr. Sanders replied, "and you would feel some discomfort from the heat. Special arrangements will have to be made to protect the ship. The reason the course is laid so close to the sun is that you will gain speed that way, in addition to shortening your course. Your ship, when you turn off the power, will he a free body, exactly similar to a comet, and you know, of course, that the closer such bodies pass to the sun the greater is their speed."

I took up the diagram and studied it while I turned the proposal over in my mind. While I had no desire to sacrifice myself to no purpose, I was perfectly willing to undertake a long chance in the hope of aiding the men who were trapped on the distant planet and at the mercy of unknown enemies. Gn its face the plan seemed hopeless, but was it? I knew that astronomers were able to calculate with the utmost precision the course of comets which appeared suddenly in the solar system, swept around the sun and disappeared in far distances. Why, then, should they not be able to prescribe the conditions under which a body would follow a desired orbit around the sun? I knew, too, that the world's best astronomers and mathematicians were at the call of the Commission for Venus. If they authorized the attempt-

"I'll do it," I said. "You say the start can't he made until the 21st?"

"It will take that long to make the necessary alterations in the ship to be used," Dr. Sanders replied.

As he stood up and took my hand with a quick nervous motion I realized that Dr. Sanders thought my death warrant had just been signed.

"There is to be another meeting of the Commission this afternoon," he told me. "You will he present, of course, and the plans for the trip will be discussed."

CHAPTER IV.

The Trip Begins.

AHEAD of me millions of stars glittered with Magnificent brilliance against the black background of limitless space. Exactly 30 degrees to the right hung the sun, a big ball of lire outlined sharply against blackness. Through the double glass port in the stern of the space ship I could see the Earth, brightly lighted by the sun, filling most of the sky behind me.

It was July 21, and my big adventure was already an hour old. After two weeks of steady work the small space ship had been remodeled to fit the special requirements of the voyage around the sun. In addition to the heating arrangement it bad been equipped with a refrigerating system which would carry the intense heat from the sun-side to the offside of the ship when I neared the sun. Special expansion plates had been inserted in the outer steel envelope of the ship to permit both extreme contraction from the cold of interstellar space and extreme expansion from the sun's heat when it became intense. The work had been completed on schedule, and I had stepped into the ship at the appointed hour after a final handclasp with Dr. Sanders.

My schedule permitted of no delay. Immediately after leaving the earth's atmosphere I had turned on the rocket power full force, so that I was now many thousand miles out on my long journey.

For my own use I carried twenty tanks of liquid air and five tanks of fuel mixture, enough to keep the ship going at full speed for forty days and to cover approximately 70,000,000 miles as well as supply air inside the sealed ship for sixty days. Packed away in the ship were ten extra tanks of fuel mixture for. use in the big ships stranded on Venus for lack of it. I had already turned on the heating system and it was warm and comfortable in the inner shell of the vacuum ship.

With the ship set on its course and running smoothly I was able to leave the controls for the time being and watch the earth, from which I was receding at more than 20 miles a second. The earth, itself rolling along its orbit at the rate of more than 18 miles a second, had already moved a considerable distance to one side of a straight line behind the ship. In the days that followed it would steadily dwindle in apparent size until it became lost in the myriad of bright specks that surrounded me on all sides and that represented worlds and suns at incomprehensible distances.

Almost squarely abeam on the right side, and at right angles to my course, was an exceptionally bright luminary which I knew to be the planet Venus. If I could only turn and fly directly to it my journey would be a comparatively simple one, but I knew that I should require years to catch the planet if I set out to pursue it through its orbit. Long before that time my supply of liquid air would be exhausted. Instead of following what appeared to be the natural course I must trust myself to mathematical science, which declared that the sun, if permitted to exercise its influence, would whirl my ship around it in such a way as to intercept the planet at an advanced point in its orbit.

As far as the theory went, I was satisfied that I would reach Venus in safety. I had only to follow the course laid out for me and there was little danger of my ship missing Venus completely and hurtling far out into space to drift there long after I had suffocated for lack of air. The chief dangers that confronted me were three in number, and I was well aware of them.

The first was that I might miss my way in the maze of the heavens. Of this I was not much afraid, since I was able to check my course both by the constellations and by the sun. Even if I became hopelessly lost I might be able to reach Mercury and replenish my supply of liquid air.

The second and probably the greatest peril would be faced when my ship swept freely in its orbit close to the sun. If the cooling system failed to work properly the plates of the outer shell might be melted. This would not only disable the ship but would permit the rays of the sun to beat on the inner shell and raise the temperature to a point where human life could not exist. Here, too, however, if my equipment worked properly all would be well.

The third danger was that which every space flier encounters—the possibility of his ship being disabled by collision with a large meteoric particle. With watchfulness and care this could be avoided, despite the fact that I would have to spend some eight hours of every day asleep. There was, of course, an almost steady succession of taps audible inside the ship as small particles ricocheted off the stream lines of the outer shell, but these offered practically no peril.

THINKING over these matters as the long journey began I felt, with the confidence of youth, that the success of my venture now depended solely upon me, and that I should prove equal to the task.

The warning bell rang, and I moved forward to the controls. An indicator, operated by a magnetic needle which reposed in a hemispherical shell of lead on the nose of the ship, showed that the meteor was approaching from above and to the left, and I quickly picked it out in that direction. It had the appearance of a star which rapidly grew in intensity. After a minute the side of it turned to the sun had assumed the appearance of a half moon toward which I was rushing with frightful velocity. The bell continued to ring at intervals of a second, growing steadily louder. I realized that the meteor was an unusually large one and stood waiting with my hand on the control, although it seemed certain, judging from the direction of the particle, that I would clear it by a comfortable margin. Alertness of vision and quickness of response in such meetings may spell the difference between safety and sudden extermination. In this case, however, the meteor was in a plane considerably above that in which I was traveling. Three minutes after the first warning I saw it flash underneath as a long streak of light. I could follow its course behind the ship for some five minutes before it became too dim to distinguish.

That danger past, I busied myself about the ship, seeing that all was functioning properly, and accustoming myself to its motion. The manifestations of gravity, as ordinarily felt on the earth, were rapidly disappearing as my distance from the earth became greater. There was no downward pull, and I was able to remain standing on the floor only because of magnetized shoe soles. Instead of a downward pull there was a steady force exerted in the ship toward the stern exactly resembling gravity and due to the fact that the ship's speed was then increasing at a steady rate under the propelling power of the rocket motor. Everything in the ship's interior was fixed in place, otherwise all would have collected in a pile in the stern. I was able to keep my place by resting my hand on a rail which ran around the interior. A strap attached to a belt around my waist could be hooked onto the rail whenever I wished. There was, of course, no night or day on the space ship, since the sun would hang for many earth days in the same apparent position. It was necessary for me to sleep, however, and I soon found myself tired after the exertion and excitement of the start. I accordingly decided to take a nap, depending on the warning bell to notify me of the approach of any large meteoric body. I ate a capsule of food concentrate, drank a glass of water, and then lay down for my first sleep on the trip.

CHAPTER V.

Past the Sun to Venus.

ON the fifteenth day of my journey—for I had of course kept a careful record of the passage of time by earth standards—I turned off the rocket motor, leaving my ship free from then on to describe the course imposed by the sun. It will be understood, naturally, that I had power Quail-able at any moment for an emergency such as the necessity of avoiding a meteor. The earth had long since ceased to present more than the smallest disk to the naked eye, and was distinguishable chiefly as the brightest of the millions of stars and planets which I could. see. It was located, to use a convenient nautical description off the starboard quarter of my ship, while the sun appeared off the starboard bow. At that time Venus was to be seen slightly abaft of the starboard beam, for I was now inside its orbit and actually traveling away from the planet, as I would be for many days thereafter until my ship swung around the sun and headed down the home stretch of the long trip. Venus then appeared slightly less bright than Earth.

Observations taken four days earlier, when I crossed the orbit of Venus, had showed that the ship was shooting through space at the scheduled rate. On the fifteenth day approximately one-sixth of the trip measured in distance, and one-third measured in time, had been completed. Since getting clear of Earth I had gradually altered my course nearer the sun. At the time I turned off the power the ship was rushing headlong "down hill" toward a point in the heavens about 25 degrees from the sun.

It was with a curious feeling that I threw the switch which stopped the action of the rockets. I was 36,000,000 miles from Earth, and considerably further from Venus. With the power off I had no more sense of motion than persons on earth realize their motion through space on the Earth's journey around the sun. Nevertheless I knew that my ship would continue to rush on its predetermined orbit, gathering speed steadily "until it whirled like a comet around the far side of the sun and headed back to Venus. My average speed during the remainder of the trip would be double what it had been while the rockets were in operation.

With the motor turned off I could no longer detect anything resembling gravitation inside the ship. I can explain this condition beat by asking my reader to imagine a closed room or box which is falling from a great height in a vacuum, and to imagine that he sitting at a table in the room. The room will be falling perfectly freely under the influence of gravity, and its occupants, human and otherwise, will be moving under exactly the some force, Then if the man holds a book at arm's length and releases it, its position within the room will not change, since both the book and the room are falling at the same rate. In other words the book will remain suspended freely in the air of the room. The table and chair likewise may be raised and will float in the air. The man may then sit in the chair or on the table, or float about at pleasure through the room by pushing himself away from the ceiling, floor or walls He can walk with equal ease on any of the six walls of the room. This illustration is exactly analogous to the condition of my ship as it fell through interminable space on its strange journey.

The succeeding days passed monotonously, except for occasional brief periods when the alarm announced that a meteoric particle of considerable size was in the vicinity. But despite the monotony I felt a growing tension in my mind. I stood frequently at the controls watching the sun, whose size now appeared double that as seen from the Earth. The dial on my instrument hoard began to show that the outer starboard plates were becoming heated, and on the 23rd day out I switched on the refrigerating system which aided in carrying the heat from that side to the port side, from which it would radiate into space.

THE sun grew larger perceptibly during the next 48 hours, until I was finally able to distinguish individual tongues of flame licking out hundreds of thousands of miles from its surface. It finally appeared squarely at right angles to the direction of the ship, and I knew I had reached the most critical part of my journey, when the ship would swing around the arc of its course nearest the sun. That my cooling system was working perfectly was demonstrated by the fact that the outer plates on the sun side, while very warm, were well below any dangerous temperature.

For the next five days, from the 25th through the 30th of the trip my ship, my ship would remain at about the same distance from the sun, speeding through the long curve around it at more than 90 miles a second, or a million miles every three hours. In the five days it would cover 40,000,000 miles.

Although this was the most critical part of the journey, and I wished to remain on guard as much of the time as possible, it was not to be expected that I could stay awake constantly for five days and keep my faculties in a proper condition to meet the emergencies that might arise. It was better to take a minimum of rest, depending on automatic signals to awaken me if any occasion arose. Accordingly after 20 hours of the critical period had passed without incident and when all appeared to be going well, I lay down for a nap. I was dangerously exhausted, and slept soundly for six hours.

When I awoke the first thing I noticed, upon looking out of the ship's ports was that the sun was no longer squarely abeam and at right angles to my course. Instead it had dropped hack fully fifteen degrees. I was seriously alarmed by this observation, the significance of which will be obvious to the reader. It meant nothing less than that my ship, instead of following its plotted course, was heading away from the sun.

As quickly as possible I took observations of the apparent position of the fixed stars. This verified the fact that the ship's direction had swung away from the sun, and revealed, moreover, that the angle was slowly increasing. Calculations made from the figures I obtained showed that if the tendency continued for 36 hours the ship would be headed directly outward from the sun.

The situation appeared fraught with the greatest peril, since my ship was traveling so fast under the influence of the sun's attraction that it was practically out of control by means of the rocket motor. Moreover its action appeared totally contrary to all known laws about the movements of astronomical bodies. The only explanation I could think of was that the ship actually was traveling much faster than I had calculated—so much faster that the sun was unable to hold it, with the result that it was flying off from the sun in entirely the wrong direction. In that case I knew that the rocket motor would be able to exert only a fraction of the power necessary to right it.

The only reassuring observation that I made was one which showed that my distance from the sun had grown slightly less, rather than greater. The apparent size of the sun was larger than it had been when I went to sleep and the tongues of flame licking cut from its surface were more distinct. This was in accordance with my mapped course which should have brought me at that time to about the nearest point of the course to the sun.

A moment's calm reflection gave me the answer to the strange problem, and showed that my only real danger had been that of becoming panicky and doing something which I would have been unable to undo later. The ship, in fact, was following exactly the course laid down for it, despite the fact that its nose was now pointing further and further away from the sun. What had happened was that when the ship began its curve around the sun there was no force to change the direction in which the ship pointed. In the Earth's atmosphere, of course, the air pressure on the stream lines would have held the nose of the ship straight. The vacuum of space offers no such resistance, and with the rockets turned oil there was nothing to prevent the ship from traveling sidewise or even tail first. In fact, I saw that if left alone the ship actually would be going tail first when it reached the end of the arc around the sun and swept on toward Venus. Nor would that have mattered except for one thing—tile cooling system was arranged to apply only to the right side of the ship and it would be fatal to expose the plates on the unprotected left side to the intense rays of the sun.

I accordingly turned on the rocket power slightly, and by inclining the exhaust to the starboard side, pushed the tail to the left. When the ship had assumed its correct position relative to the sun, I straight-cued the exhaust to stabilize it on the course and then again cut 05 the power.

BEFORE I again lay down for a nap I had the satisfaction of seeing an exceedingly bright planet appear from behind the sun. It was Venus, which the day before had been lost to view as I swept around the far side of the sun from it. At last I was on the home stretch, and headed for my goal.

What, I wondered, had been the fortune of the party of colonists in the meantime? Had they again established wireless communication with Earth after a silence forced by some circumstances of which I could know nothing? Had the lost men returned, the tanks of fuel mixture been recovered, and would I find the camp firmly established and all going well?

Or had the mysterious raids on the camp been continued? Would I perchance find that the entire party had been wiped out and that I was the only man alive on the planet? In the latter case the chances would be heavily against my survival, although I would be forewarned of danger and on guard from the first.

These restless speculations engrossed my mind more and more during the days that followed, as the planet Venus steadily grew larger to the eye. I could tell that my ship, sweeping through space at a tremendous rate, lessening however as it receded from the sun, would almost exactly strike the planet. That was well because. although I could easily fly under power to the planet from my position inside its orbit and slightly ahead of it, I wished to save as much fuel mixture as possible. It might prove necessary to attempt to return to Earth in one of the larger ships at the next inferior conjunction and in that event the extra supply of fuel mixture which I carried would be none too much.

In the final stage of my journey the ship was traveling about at right angles to the motion of Venus, and the two bodies were converging with a tremendous mutual velocity. From an apparent size equal to that of the moon seen from Earth, the disk of, Venus perceptibly enlarged. It became obvious at length that, if left to follow the orbit into which it had settled, my ship would crash into the planet—so exact had been the calculations of the astronomers of the Commission.

When still about one million miles off I turned on the power and altered my course toward a point somewhat in front of the planet. I then began reducing the speed of the ship, using the rocket power as a brake. Twelve hours later my journey was practically finished as I hovered over the northern hemisphere about a hundred miles from the surface of the planet, but well within its atmospheric shell.

CHAPTER VI.

The Raiders.

FROM a great height the continent of Elysia looked like a green carpet spotted with patches of white and brown. Below me I recognized the contours of a large peninsula which my map showed to be about 200 miles east of the mouth of the Holmes River. Before setting out for that point I dropped lower to view the surface of the planet at close range.

The green carpet was a forest of trees which I estimated to be all of 200 feet high, and it stretched inland as far as the eye could reach. Their tops were waving in a breeze hardly perceptible otherwise, and above them "there was no sign of bird life or life of any sort. When I swooped down close to the water, however, I saw a group of large reptilian animals slither into a marshy backwater from the bank, where they had been sunning themselves. I mounted to an elevation of about 1,000 feet and headed westward toward the destination of my long journey. After 4-5 days spent alone in the small space ship I had the strongest desire to set my feet on solid ground again and to find someone of my own kind to talk to.

After half an hour, about the time I had allowed myself to cover the 200 miles, I saw that I was approaching a wide indentation in the coast line, which I judged to be the mouth of the Holmes River. Two miles upstream I should find Commander Jones' camp.

As I came nearer, however, I saw with surprise what appeared to be evidence of man's work on a bluff on the far side of the wide bay. The top of the bluff had been cleared and levelled off, and on it had been erected a dome-like mound of earth resembling a large Eskimo igloo. There was a circular opening in the top, and other openings, apparently entrances, around the circular base. The fresh dirt gave evidence that the structure, whatever it was, had been finished comparatively recently. The idea which leaped to my mind as I tried to explain this unexpected discovery was that Commander Jones had deserted his first camp for some reason and had moved to this point, two miles down, at the mouth of the river, and had erected this strange habitation. Why, then, had no one come out to welcome me?

The most logical answer was that, believing it impossible for anyone to make the trip from Earth at the time. they took me for an enemy. I hovered low and permitted my ship to drift over the mound so that if any of the party were concealed there they could recognize the ship as an Earthly one. When I came directly over the opening I could see that the mound was hollow. I could make out nothing in the dimly lighted interior, and there was still no sign of life. As I searched the strange mound with my eyes, however, I saw a pencil ray of intense light suddenly directed from somewhere within it at my ship.

Almost immediately I saw a wisp of smoke from the floor of the ship near the stern. The ray was cutting through both inner and outer plates with the ease of an acetylene torch flame eating through a thin sheet of lead.

I sprang to the throttle and advanced it. With a tremendous roar the ship leaped forward so that I was almost thrown to the floor. In barely a second I was out of sight of the mound over the trees which surrounded the cleared bluff on the land side. There I again stopped the ship, letting it drift while I examined the damage. The ray had cut a semicircular arc through the inner and outer plates of the ship, and had punctured the overhead plates as well. It had come perilously close to the reserve tanks of, fuel mixture, which would have exploded and annihilated the ship if they had been exposed to it. As it was the ship had been rendered useless for interplanetary travel, although it could still be used in the atmosphere of Venus.

I had travelled some ten miles from the bluff when the ship again came to rest. After I had finished my inspection of the ship I looked about me and was surprised to notice a wide river about a mile ahead. I recalled then that I had not seen the river before. An examination of the map convinced me that in fact the bluff where the strange mound was situated was actually on the arm of a small bay, and that the Holmes River lay in front of me. I accordingly proceeded slowly to the river and turned downstream over it, since I knew I was more than two miles inland. A few minutes later I sighted a collection of huts on the right bank, and a short distance away were the two large space ships used by the Jones expedition. It was unquestionably the camp established by the party. It was overgrown with creepers, however, and gave every sign of being completely deserted. I settled down over it and saw that my judgment was correct. There was no sign of life in the camp. Carefully I brought my ship to rest near the two large space ships, and stepped out to the ground.

I was convinced that I had accidentally stumbled on the home of the creatures whose mysterious attacks had disrupted the expedition. Furthermore I had had a terrible demonstration of the power they were able to wield. I resolved that, forwarned as I was, I should not share the fate of Commander Jones and his aides, whatever it might have been. Undoubtedly the creatures would look for me at the site of the camp. As I had not seen them I could form no idea of how formidable they would be. I decided to inspect the camp hurriedly and then conceal my ship nearby and return to watch developments.

In the limited time which I allowed myself I hoped to discover some record which would indicate the fate of the colonists, and also, if the wireless set were in order, to send a message to Earth telling of my arrival. I turned first to the semicircular row of huts and searched them rapidly. The huts and their contents had suffered considerable damage from rain since being deserted. They still contained most of the personal effects of the colonists, indicating that the desertion of the camp had been accomplished in great haste. In the fourth hut which I entered I found evidence that it had been occupied by Commander Jones. There was a box containing some of the instruments taken from the space ships. On a shelf I found what I most wanted—the log of the trip. I opened it quickly and found, to my intense disappointment, that the last entry had been made on the day when the final message from the party was received by me in Washington. There was nothing to tell how or why the camp had been deserted, which con firmed my suspicion that the colonists had been overcome by a sudden attack directed from the mound on the coast.

I tucked the slightly mouldy book under my arm, to study it later at leisure, and completed a hasty examination of the camp. I was unable to understand the complete lack of evidence of an extensive struggle. The fact that there were no human remains anywhere in the camp permitted me to believe with some cause that the colonists were still alive. But whether they were prisoners or had been driven to some other part of the continent remained to be seen. My search was next directed to the two large space ships. The thin waterproof cover of one of them had been torn and the ship's plates were rusting. I entered the other one and found from a cursory examination that it appeared to be in first class condition. The apparatus for compressing and liquefying air was in seemingly good repair, but the tanks of fuel mixture, without which liquid air was useless for motive purposes, were missing.

The wireless apparatus had been set up in this ship, and a rapid examination convinced me that it had not been damaged. As I was looking over it more carefully I heard a chattering sound which seemed to come from the direction of the huts. I slipped over to one of the ports on that side. What I saw took away my breath and made my heart beats cease suddenly.

A large balloon-like object, shaped like a dirigible, had settled quietly to the ground on the other side of my space ship, and from its interior were alighting several creatures whom I felt sure were from the mound colony. In general appearance they bore a remarkable resemblance to human beings, although they were unlike any men I had ever seen. They were slightly smaller than the average man, and had large heads, big round eyes which protruded, and pointed noses and chins. They moved rapidly and alertly. They wore tunics which fell freely from their shoulders to their knees.

As I watched breathlessly, between twenty and twenty-five of these beings, presumably natives of Venus who had escaped discovery on the first exploration of the planet, alighted from the object which I could only suppose to be some sort of flying machine. Two-of them immediately walked to my space ship and after examining it from the outside entered through the open passage. The others scattered to search the camp.

I realized that despite my resolutions, I had allowed myself to be outwitted by the enemy in the first encounter. The creatures had surprised me in overwhelming numbers, and in addition, as I knew, were probably better armed than I was. Knowing that they would soon search the large ships for me, I decided that the best thing to do under the circumstances was to attempt to hide in the underbrush until they had left the camp. The space ship was on the edge of the camp and I was able to keep it between me and the creatures until I reached the protection of the trees and undergrowth. I worked my way silently further into the forest and then climbed into the lower branches of a tree and mounted to where I was able to obtain a fairly unobstructed view of the camp.

A Meeting

THE Venusians, as I judged them to be, did not seem particularly perturbed over my escape. As I watched them through the branches of the trees they concluded a search of the camp and collected around the balloon, or whatever it was, in which they had arrived. There was a conference and then several of them went to my ship and entered it. They emerged within a few minutes each carrying two of the tanks of fuel mixture. They made several more trips until all the tanks had been removed to their ship. I could see that they were preparing to leave, undoubtedly thinking that I had been rendered helpless by the loss of the fuel. I watched with the utmost interest as they entered their conveyance. A cleverly constructed door closed downward, apparently sealing the ship airtight. Then without a sound and with no means of propulsion which I could observe, the object rose in the air and headed purposefully in the direction of the mound.

I descended the tree and made my way back toward the camp. At the fringe of the underbrush as I was about to step into the cleared space I heard a rustling sound nearby to the right. I dropped to the ground, although the noise had come from so near I was almost sure I had been observed. My fears turned to amazed joy when I looked up and saw a man step from behind a tree a few yards away. It was Captain Matthew Eddy!

"Starrett!" he cried. "But how on earth—"

Captain Eddy's joy and surprise at this unexpected meeting equalled mine. He was at first unable to believe my story of the trip around the sun, but my presence and that of the small ship forced him to accept it. He then told me briefly the history of the expedition in the following words:

"You already know of the disappearance of Smith and Fall, and later of six other members of the party, and of the theft of our fuel mixture. We were totally at a loss to explain these mysteries, especially as we had every reason to believe that there were on Venus no other intelligent beings than ourselves.

"On the night following the first invasion of the camp I was awakened by a cry from the-adjoining hut. As I started up I saw two manlike creatures framed in this doorway. They immediately pounced upon me and before I was really awake they had overpowered and bound me. I was left alone in the hut for about five minutes, and in that Lime I managed to slip the knot in the wiry cord which held my arms and free myself. I realized from the sounds I heard that the camp had been invaded in force and that all the men probably had been made prisoners as I had. Knowing that the fate of the entire party might depend upon me I crept cautiously to the door and looked out. There were about a hundred of the strange men in sight, many of them gathered around what resembled a dirigible which rested in the camp. Others were carrying the bound forms of my comrades and placing them in the object—which I have reason to believe is nothing less than a space ship.

"It was obvious that if I showed myself I would immediately be overpowered and captured. The lives of my comrades appeared to be in no immediate danger and I decided that my best chance of rescuing them lay in maintaining my own freedom and watching developments. Accordingly I made a hole in the rear of the hut, and. unobserved, slipped out of the camp. I was the only one who escaped the raid. The others were all placed, securely bound, in the raiders' ship. Ten minutes later I saw the ship rise silently until it was outlined against the stars high overhead. It then headed swiftly in a northeasterly direction." Captain Eddy told me briefly how he had set out immediately in the direction taken by the raiding party, and after a week's search had found the mound colony. He had stayed in the neighborhood of the mound ever since, except for an occasional trip through the ten miles of jungle back to the camp for supplies. 'He had observed the actions of the mound men from trees on the fringe of the cleared bluff, but had seen no trace of the prisoners. His observations had convinced him. for one thing, that the dirigible used by the mound men was really a space ship of some strange kind.

"I have come to the conclusion," he said, "that the mound creatures are not natives of this planet any more than we are. They are totally unlike any other form of life to be found on Venus, and it is almost inconceivable that they have developed here so tremendously in advance of everything else on the planet. It would be no more incongruous to imagine modern men living in the same world with the prehistoric animals which roamed over Earth when it was comparatively young.

"Moreover the fact that there is only a single colony and that the party has a space ship is almost conclusive evidence that they are visitors from another planet. It is my opinion that the party came here from Mars, where, we have reason to believe, there is life similar to that on Earth."

The force of what my companion said was apparent, and I was inclined to share his view. If it were the truth, we were undoubtedly faced by the strangest situation any man had encountered. Nevertheless, that view of the situation held more hope than any other I could imagine. If the mound creatures were indeed Martians then their number was limited. If Captain Eddy and I could outwit them—find some means of freeing our comrades—the struggle for control of the planet should not be too unequal, although I was sure the mound creatures—whether Martians or natives of Venus—would prove worthy opponents. My companion told me that there were about 150 of them living in an excavation in the bluff, to which the openings in the mound were entrances. About half of them went daily in the space ship to some point west of the Holmes River, he said. As he had no way of crossing the river he had been unable to discover the objects of these trips.

Captain Eddy told me that he had made an attempt to operate the wireless set but that his knowledge of radio was not sufficient to enable him to succeed. Together we slipped into the space ship and I began working on the set.

I found that the batteries had lost some of their strength, but nevertheless I made the necessary adjustments, and began flashing the earth call at five minute intervals. Several hours later, when I was about to give up in despair, I caught an answer. I then transmitted a brief but thorough account of the supposed fate of the party of colonists, with the assurance that Captain Eddy and I would do all possible to rescue them if they proved to be prisoners of the mound men.

CHAPTER VII.

Trapped.

AT Captain Eddy's suggestion we spent the night in a tree near the camp, sleeping on a platform of boards taken from one of the huts. At dawn we ate breakfast in the camp and then set out for the coast, working our way through the light underbrush. Although the going was not difficult it was necessarily slow, and the sun indicated it was noon when we finally approached the bluff on which the mound was located. We were aided by the fact that the force of gravity on Venus is almost a fifth less than on Earth, so that while we retained our strength on Venus we lost about one fifth of our weight. Consequently we were able to walk much more lightly and to leap over obstacles which, on Earth, we would have had to climb painfully. Moreover the weight of other objects was similarly reduced, so that 120 pounds could be lifted with the same effort that would he required to raise 100 pounds on Earth.

We lunched on the sap of a milk tree in which my companion had set a spigot. The fluid tasted considerably like milk and Captain Eddy told me that Dr. Alexander, the chemist of the expedition, had found it particularly nourishing. The trees were plentiful along the coast, growing to a height of about 20 feet under the shelter of the tall trees.

We then approached cautiously nearer the bluff and climbed into a tree which my companion had found well suited for observation. The space ship was not in sight, having gone as usual somewhere to the westward. Nor were any of the mound men visible at the time. Five minutes later, however, we saw ten of the creatures emerge from one of the openings at the base of the mound. They descended the bluff and disappeared in the forest to the left.

I suggested, imprudently enough, that Captain Eddy remain where he was while I made an attempt to cross the bluff and enter the mound, in the hope of reaching the prisoners and freeing them. Captain Eddy emphatically vetoed the plan, telling me that the top of the bluff was constantly watched. He then outlined his own plan of action, which required that we remain where we were until after dark, when one of us could try to penetrate the home of the mound creatures. Captain Eddy had often wished, during the two months he bad watched the mound, that he were free to make a similar attempt. The odds against success were so great, however, and his responsibility as the only free colonist was so great that he had not risked it. Now that there were two of us he agreed with me that the effort must be made. At my insistence he agreed that I make the attempt, while he remained in the forest.

As we were discussing this plan in whispers I realized suddenly that the tree in which we were concealed was swinging slowly out of its vertical position. Startled, I looked down and saw, far below me, at the base of the tree, a pencil ray of light eating through the trunk. The swing toward the ground continued with increasing momentum and in a second the tall tree was crashing through the branches of its neighbors, while Captain Eddy and I were scratched and buffetted and finally torn loose from the branches to which we were clinging. The resistance of the other trees slowed our fall somewhat, but I was thrown clear of the tree when it finally crashed through, and struck the ground with sufficient force to stun me momentarily.

Before I could move two of the strange men from the mound pounced on me like cats and pinioned my arms. I struggled as well as my returning strength permitted and for a half-second flung them free. The next instant they were back, and several others dashed in to aid them. After a fierce but brief struggle one of them slipped a noose over me and drew it tight about my arms. I was rendered helpless and, though I continued to kick and writhe as long as possible, they quickly completed the work of trussing me securely. When I finally relaxed, realizing the futility of further struggling, I was laid on the ground. A minute later the bound form of Captain Eddy was placed beside me. I saw that he was unconscious, and that his forehead was bleeding, but I could not tell how badly he was hurt.

Our captors, who were the same ten we had seen leave the mound, chattered briefly among themselves, and then Captain Eddy and I were picked up and carried up the bluff and into the mound. After carrying us through a short passage from the entrance our captors descended a long flight of steps cut in the dirt. The lower level was lighted with a soft pleasant glow the source of which I could not determine. A large central arena was revealed, with cells around the walls and with six passageways running off at intervals of sixty degrees. We were transported clown one of these passages for about fifty feet—half of its length—and the party halted in front of a door. One of the mound men turned several levers, and then swung the door open, revealing a vestibule about ten feet wide and fifteen feet long, with a closed door at the far end.

WE were laid on the ground in the center of the vestibule and the mound men departed, closing the door through which they had carried us. Some thirty seconds elapsed and then there was a sharp click. Immediately the inner door opened and Commander Jones and several others of the missing colonists appeared. They did not seem particularly surprised to see the form of Captain Eddy, but their amazement when I was recognized can be better imagined than described. Our mutual exclamations were interrupted after a moment by a low musical note from the inner room. Apparently it was a warning.

"Quick!" Commander Jones ordered in a sharp voice; "Drag them in!"

Friendly hands grabbed me and dragged me, still bound, through the open door. Others carried the still unconscious Captain Eddy into the large room which was revealed, and the door then snapped shut.

Commander Jones turned his attention to Captain Eddy, while others quickly unbound me. My companion had suffered a bad cut on the back of his head. He revived as his head was being bathed with water taken from a small channel which led through the underground chamber, and it was found that his wound, while painful, was not serious.

Commander Jones then listened with the utmost interest to a recital of my trip from Earth.

"We heard something of your arrival from our jailors," he said, surprisingly, "but it seemed so incredible that we decided there was some mistake. As for poor Eddy, we have had regular reports of his activities. While he thought he was unobserved he has been under constant surveillance and could have been captured at any time during the two months we have been held here."

"Do you mean that you can communicate with your jailors?" I asked, "And for that matter, who and what are they?"

"I can tell you everything that we know about them very quickly," Commander Jones said.

"Soon after we were made prisoners I was taken into an office in another part of this ant hill. There was a recognizable map of the heavens on a table. One of our captors who acted as spokesman indicated Earth on the map and pointed to me. I nodded my head, foolishly thinking that he would understand that affirmative sign. When he failed to do so I touched my chest with my finger and then placed the finger on the dot indicating Earth. This he understood, and in a like manner he told me that he and his companions came from Mars.

"He then touched himself and indicated his companions. Placing his finger on Mars he traced a path to Venus. Then he nodded his head vigorously. I was forced to laugh, as you would laugh at a monkey, by the celerity with which he had adopted my sign of affirmation once he understood it. I realized, however, that he was no monkey, but a being of quick intelligence. But his message was not completed. He next indicated Earth on the map and traced a path to Venus, and then made a sign of breaking something in his hands. The meaning was plain enough. He was telling me that Venus should belong to the men of Mars and not to the men of Earth. My reply was to show my defiance in the same manner he had adopted.

"Since that day I have had many conferences with the same individual and we have developed a means of communicating ideas with a minimum of effort. I have picked up some of their vocal sounds and he has learned a remarkable amount of something approximating English. Although there is a certain amount of friendliness between us because of this ability to understand one another, his enmity as a Martian against all Earth men, and his determination to keep Venus for his own race is unaffected.

"The present expedition of Martians numbers about 200 and they have been on Venus for more than two years. During that time they have not been able to communicate with Mars. I was surprised that they had not developed wireless until I learned that they have the ability of transmitting thought very efficiently. This, of course, made wireless unnecessary on their home planet, but it cannot be used for more than a few thousand miles.

"As a result of this the party must return to Mars to report the success of their trip and their discoveries here. They are planning to leave within a few weeks, when the position of Mars will be favorable. Then at the next favorable conjunction they plan to return with other ships and several thousand of their fellows. They expect that ten years from now the entire population of Mars will have been transferred to Venus, since Mars is rapidly becoming incapable of supporting life. The population of that planet now is only about a million, as nearly as I can make out.

"One thing they have given me to understand very definitely. Before they leave Venus they plan to kill all of our party, not out of any feeling of enmity, but solely to eliminate the possibility that we will return to Earth for reinforcements and will contest with them the possession of Venus. The idea has never occurred to them that the men on Earth already know of the success of our trip and the nature of conditions on Venus."

"BUT can't we do anything?" I protested.

"We have not been inactive," Commander Jones replied, "and we have high hopes of escaping and outwitting them. I must explain to you first the nature of our prison.

"The walls are charged with an electric current at high tension and it is only necessary to press on them to receive a very severe shock. Since the connections are behind the walls we are unable to get at them, and it would do no good if we could. because they would know it immediately if the current were interrupted. They have a special connection by which they can permit us to go into the vestibule to get food they have left there, but if we linger the current is switched on. Our water we get from the stream running through the end of the room. It drops to a lower level near the wall, you see, and serves there to dispose of waste. It is the system of plumbing which they have provided for the entire colony."

He led me over to the wall beyond the small stream and raised a box which rested there. Under it was a hole about three feet across leading down into the ground.

"Soon after we were imprisoned here we began working on a tunnel under the walls, disposing of the dirt in small quantities by letting the stream carry it out to the ocean. It is now completed to within a foot of the surface near the base of the bluff on the land side, and we are only waiting the propitious moment to put out escape to the test."

Commander Jones next led me to the double row of bunks in the center of the room. Under the foot of one of the bunks he pointed out two containers which I recognized as cans of fuel mixture.

"I found out where these were kept," he explained, "when my Martian captor questioned me about them. These two are all I have been able to slip in here unobserved on my various trips into the other parts of the ant hill. They will serve our purpose; I think."

While others of our fellow prisoners gathered around us Commander Jones explained to me the plan that had been worked out. The tunnel could be forced through at the base of the bluff at any time by a few minutes' work. Our leader thought it best to wait for a few days, until the exact plans of the Martians were revealed, and make the break for liberty at the last moment consistent with safety. Two of the men would slip out under cover of darkness, carrying the two tanks of fuel mixture with them, and make their way to the abandoned camp where the two large space ships and my small one were deserted.

A highly explosive bomb could be made by injecting a small amount of the fuel mixture into one of the heavy tanks of liquid air. Using the rest of the fuel mixture to operate one of the ships, the pair would return over the mound and drop the bomb on it. The attack on the mound would he timed exactly, and before it was made the remaining prisoners would slip out through the tunnel and escape to a safe distance from the bluff.

There was a large group of the colonists who chafed at the proposed delay in action. It was their argument that the Martians might at any time decide to carry out their announced plan of doing away with all of us. It was argued that their capture of Captain Eddy and me, putting all of the Earth men on Venus in their power, indicated that the crisis was near. At any moment they might introduce into the underground chamber a poisonous gas which would give us no chance of resistance, or of using the tunnel.

This faction proved the more weighty, and when Commander Jones acceded to the wishes of the majority it was decided that the attempt should he made that night. Commander Jones refused to leave what he considered the position of greatest danger, nor did Captain Eddy's condition permit him to indulge in anything so strenuous as a ten-mile trip through the forest. Commander Jones accordingly appointed Arthur Rhodes, one of the most resourceful members of the party, as one of the pair to make the attempt to bomb the mound. I was picked as his companion because of my familiarity with the operation of both the small and the large space ships.

About an hour before dawn the following morning Rhodes slipped head first into the hole in the floor and wriggled out of sight. I followed, although the dark hole was anything but inviting. I made my way through the tunnel more slowly than my companion, pushing the two containers of fuel mixture before me. When I finally touched his foot with my outstretched hand he whispered to me to lie quietly for a moment. He had already removed some of the dirt at the end of the passage. After a moment, when no sound reached us, he resumed work, passing back handfuls of dirt to me, which I distributed on the floor. After a few moments I felt him slip forward and then felt a breath of cool air. I silently wriggled forward and slid out of the and of the tunnel. We placed a piece of brush over the opening and then slipped into the forest carrying our burden, apparently unobserved.

We proceeded slowly until sunrise, after which we were able to make better time. Considerably before noon we came to the river bank and soon located the camp. We had decided to use one of the large ships, since they were equipped with chambers in the floor through which the bomb could be dropped. We accordingly set to work at once dismantling the aerial posts from the ship which was in the better condition of the two. That completed we entered the ship and continued our preparations, arranging the powerful bomb and fixing a fuse to it.

All was in readiness long before night, but we were forced to wait until the prearranged hour to give our companions an opportunity to escape from their prison.

CHAPTER VIII.

The Battle in Space.

AN hour after sunset we closed the door of the big ship. I loosed the rocket power and the ship rose swiftly to a height of several hundred feet, where I steadied it. As it would take no more than a few minutes to arrive over the mound colony, Arthur Rhodes was already stationed at the center of the ship, where the improvised bomb lay in the chamber in readiness to be dropped. His voice came to me over the telephone.

"O. K. Let 'er go!"

I turned in the direction of the mound and picked up a speed of about 200 miles an hour. I did not wish to go too fast as it would be necessary to slow down over the bluff on the sea coast so that my companion could drop the bomb accurately. He would have enough difficulty in any event in aiming the missile through the glass port in the floor. Even so, we were in sight of the mound in four minutes.

As I reduced the speed of the ship I saw a dark object rise swiftly over the mound. There was no sound, but in the dusk I could make out the outlines of the Martian space dirigible, which was shooting upward with increasing speed.

It seemed obvious that the Martians had discovered the escape of their prisoners, and had acted so quickly as to entirely upset our plan. How many of the party were in the big ship I could only guess, but it seemed best to carry out the plan' of destroying the mound, where I presumed the majority of them remained. I accordingly held the ship on its course. When almost directly over the bluff I saw a figure run out on it with a blazing torch. By the indistinct light I realized that it was one of our own party. Lest Rhodes should fail to recognize him and drop the bomb, I swerved seaward quickly to prevent the ship from passing over the bluff.

As I did so I suddenly understood the significance of the signal some member of our party had risked his life to give. For some reason, at which I could only guess, the Martians had entirely deserted the mound. All of them, then, must be in the space ship. Could it be that they were departing for the long homeward journey? Had they discovered the escape of all their prisoners and started to search for us at die deserted camp, only to change their plans when our ship came in sight as they took off?

These conjectures flashed through my mind instantaneously. I automatically turned the ship upward and advanced it to high speed in pursuit of the Martian ship. As I did so, the voice of Rhodes came to me from the center of the ship. He had not seen the Martian ship, and was unable to understand what had occurred. Receiving only disjointed exclamations in answer, since all my attention was devoted to the pursuit, he came forward to where I stood in the bow of the ship. By that time I had collected my ideas and was able to tell him in a few words, what apparently had occurred. The Martian ship had disappeared from our sight, but from its course while it was visible I judged that it was still mounting upward from the surface of the planet.

Rhodes agreed with me that we should attempt to overtake the Martian ship and disable it, if possible, rather than permit its occupants to reach Mars and return with reinforcements. We had seen that the Martians were intelligent and resourceful, able to use weapons which gave them a decided advantage over us, and absolutely ruthless in their determination to hold Venus for their race and to wipe out all competitors. They had openly declared themselves our enemies, and we were forced to regard them as such.

Although the sun had set an hour earlier on the surface, our swift flight upward brought into view first a reddish glow in the west, and then the rim of the sun itself appeared. Strain our eyes as we might we were unable to see the Martian ship. I pushed the space ship to the limit, increasing its speed steadily as the atmosphere became less dense. We shot swiftly through the upper layers of atmosphere and soon emerged into the blackness of interplanetary space.

"There it is!" Rhodes cried.

I looked in the direction he indicated and saw a thin crescent of light overhead and to the left. It was undoubtedly the Martian space ship, shining moon-like by the light of the sun. Against the completely black background of limitless space it was impossible not to see it. Could. we overtake it?

I COULD hardly doubt that we had been observed by the Martians as soon as we emerged from the atmosphere of Venus, but I decide upon a ruse. If I could place our ship directly between the Martian and the Sun we would be invisible to them, while their ship could be seen in its largest and brightest form. I accordingly cut to the left and in five minutes accomplished my purpose. Although we had lost valuable distance in the race to overtake the Martians, we now had a distinct advantage in being visible to them, if at all, only as a small speck on the disk of the sun, while their ship shone like a large moon before us. The question now was one of speed.

We had about a day's supply of fuel mixture. However, since our ship was not designed for space combat our only way of disabling the enemy ship was to drop the improvised bomb on it. I realized, of course, that this could not be done except under some gravitational force. If attempted outside of a fairly strong gravitational field the bomb would not "drop" but would continue to travel with our ship until it exploded and destroyed us. The only chance of success, a slim one at best, was to make the attack while still within the gravitational field of Venus. I accordingly pushed the ship to the utmost, and had the satisfaction of seeing the Martian ship grow larger in appearance, showing that we were overtaking it.

While the description of these events has taken considerable lime. the reader must understand that their actual occurrence covered only a brief span. We were already, however, some 10,000 miles from the surface of Venus and it was apparent that we would be 15,000 miles up before we could overtake the fleeing ship. I made a rapid calculation in my head. The attraction of gravity at the surface of Venus is about 26 feet a second. At 15,000 miles the acceleration would be less than two feet a second. However that would Suffice if my plans worked out otherwise.

Rhodes fell in with the idea completely when I sketched it in a few words.

"I'll put a ten-second fuse in the bomb and let you know the moment I release it," he said.

Left alone in the control chamber in the bow as my companion hurried back amidship, I watched the Martian ship grow steadily brighter. I wondered if the enemy ship, like ours, was entirely unfitted for fighting. If they were able to direct that powerful ray of light from the ship we were doomed, for once the double shell of our ship was punctured we could not survive in the vacuum of space. That was a chance we were forced to take.

It was only a few minutes before our ship was quite close to the Martian. The superior speed at my command enabled me to manoeuvre the enemy into position between our ship and the planet below. I then let the space ship sink gradually until it was speeding along a course directly parallel to that of the Martian, exactly above it relative to Venus, and separated by no more than fifteen or twenty feet.

"All set?" came the steady voice of Arthur Rhodes.

"All set," I replied.

In my mind's eye I could see him light the fuse, close the inner door of the chamber and open the outer one.

"It's off!" came his shout over the telephone.

I held the ship steady for two nerve-wracking seconds to give the bomb time to clear it, and then again turned the rockets on full force and directed the ship sharply upward.

With the nose of the ship pointed away from the Martian ship, I was unable to see what happened next, but when I turned some ten seconds later at a distance of more than a hundred miles from the point where the other ship should be, it could not he distinguished. Instead, I could make out several large luminous particles, and I knew that innumerable smaller particles of what had been the Martian ship had been flung off in every direction.

Arthur Rhodes, who joined me in the control room, had actually witnessed the breakup of the Martian ship. No noise of the explosion had reached us, of course, since sound is not carried through a vacuum.

The large pieces of the' ill-fated ship had been flung down toward Venus in different directions. Soon after our ship reentered the atmosphere of the planet we saw one of these particles flash through the atmosphere as a flaming meteor or "shooting star."

It is necessary only to add that Rhodes and I joined the other colonists and that the interrupted work begun on the radium field was resumed. A few days later we discovered what had taken the Martians daily to the westward of the Holmes River. Several miles west, on another seacoast bluff, they had built another colony such as the one which Commander Jones called an "ant hill." Doubtless this had been intended as a home for others who were to he led back to Venus by the exploring party. However, the Martians apparently deserted the plan of colonizing Venus when the party of explorers failed to return, and none of them have since appeared on Venus. The Earth colony there has of course grown to important proportions and the inspired dreams of Dr. Sanders, head of the Commission for Venus, bids fair to be not only fulfilled, but surpassed.

THE END