When Robin Carew opened his eyes, he knew he was a very sick man. He felt warm, sticky, and he hurt all over. He tried to sit up, but everything spun dizzily around him. His arms, legs, and body were burning intolerably and there was an itch throughout him that he could do nothing about. He lay back, trying to gain strength.

A little later he managed to crawl to the water's edge, fill the container he had used in the trip from Earth, drag himself back. For a period whose length he could not determine he lay helpless in fever and pain, arousing himself only long enough to drink to soothe his tortured body.

Finally, the fever broke. He sat up, feeling weak but with his mind clear at long last. He dragged himself to his feet, blessing the light gravity, aware that if he were back home his body would not have responded. He felt that he was gaunt, he knew he had been through a terrible siege, and he could only guess at the time he had lain there, tossing about on the strange Lunar ground, unprotected in the queer climate of this unknown cavern. It must, he felt, have been days—Earth days, of course—that his attack had lasted.

Later on he decided that he had suffered from a severe case of space burn. Having traveled through the emptiness of the void between the planets, the vessel had been nearly unprotected from the cosmic rays and the more penetrating of the sun's invisible rays. He considered himself lucky to have survived at all.

He desperately needed food now to rebuild his body. He looked at the rabbit pen. The little animals were there and evidently prospering on the ball-food he had prepared for them before his sickness. It was almost all gone and he broke open and pared more at once. He wondered how long it would be before the animals bred—he knew that rabbits bred fast and abundantly, and hoped it would hold true on the Moon.

There was a sudden chattering in one of the strange trees and he looked up to see a little brown face peering at him. In a moment, the monkey leaped to the ground, then leaped in one tremendous jump to Robin's shoulder and perched there happy at finding companionship again. The monkey looked none the worse for its experience and evidently was getting along nicely on the Lunar vegetation. Thus encouraged, Robin fed himself, first carefully testing everything on the monkey, who objected to nothing.

But somehow the food was not entirely satisfying to the man, who felt that he needed more than that to recover his full energy. He looked again at the rabbits, looked also for the carcass of the dead one. But he found that part of it had rotted and part had been consumed. He looked closely and saw his first glimpse of a Lunar counterpart to animal life.

There were many tiny creatures, a half inch to an inch in length, looking at first like ants but on closer inspection appearing more like three-segmented worms, for they lacked legs and moved in an inchworm's fashion. Instead of antennae, each little worm-ant had on its front segment a single upstanding stalk ending in a little yellow ball. Robin touched one of these and it glowed momentarily. An organ of light, he thought, something like the ones carried by deep-sea fishes. The tiny things were eating the dead rabbit.

Robbin went back and examined the three remaining rabbits. Two were males and the female was evidently heavy with young. Well, he could afford to dispense with one of the males, then, for he knew his body needed meat.

He put the rabbit back though, realizing that first he must make a fire and determine how to cook his meal. He searched his pockets. He was wearing the GI jacket he'd taken from the soldier in Las Cruces. As he had hoped, he dug up a pack of matches in one pocket. He turned it over in thought. When this pack was used up, how could he make fire?

He piled some trunks of dead tree stalks in a cleared spot; he lit them with one of his matches. They caught fire rapidly and soon he had a nice blaze going. He watched the smoke rise and saw that it drifted rapidly away in the same direction the current was flowing—evidence of more caverns somewhere beyond.

He opened his scout knife, hesitated. He'd never cooked a rabbit before. In fact, he'd never had occasion to cook anything for himself. It was meat, he thought, and even if it were eaten raw—well, savages did, so he, too, could manage. He thought about boiling it in water, then realized that the light air pressure might allow water to boil without getting the necessary cooking effects. The best method therefore was to fry it where he could observe the progress.

Steeling himself, he seized the rabbit, killed and skinned it, the latter a process which he found thoroughly unpleasant. Cleaning it of its entrails, another unpleasant task, he cut the meat up into sizable chunks, skewered a couple of pieces on a metal rod which had been part of one of the cages from the rocket, and sat down to cook it over the open fire.

It turned out to be a longer job than he'd thought, and he burned the meat quite thoroughly in the process, but finally he made it edible and chewed it slowly. He needed salt, he realized, and wondered if he could find any. This would have priority when he began his explorations.

He hung the balance of the meat on a ball-tree with a piece of cord. He had seen no evidence of flying insects or creatures, and hoped thereby to be able to preserve the rest of the meat.

Thus fed, he sat down and began to map out his course. I must do things systematically, he told himself. I must keep track of time, set up a regular pattern of living, find a permanent base of operations. I shall have to explore this cavern and those beyond it, find all possible enemies and invent ways and means of defending myself. I shall have to breed my rabbits in quantity, find a way of using their pelts and fur. I shall have to determine a use for everything left from the rocket's material—metals and the like.

For, he continued telling himself, my one aim shall be to stay alive long enough to be found some day by exploring rockets from Earth. I am a Robinson Crusoe of a new world. Crusoe waited twenty-eight years for rescue, I must be as courageous. In his case, he had no evidence that any ship would ever bother to call on him. In my case I know that rockets are being made that will eventually lead to further Moon trips. I know that men are planning to come here. I must wait it out, even for twenty-eight years.

But it was not that simple and he knew it. But first things first, and the first task was to survive.

With the monkey scampering on ahead, he set out to walk to the cavern wall. He found it to be dark and glistening, a lavalike sheet resembling the bubble it was. Leaning against it and looking upward, he saw that it curved gradually up, and that indeed he was in a flaw within a very porous world. Like the inside of a Clark candy bar, he thought, with a wry smile.

Astronomers on Earth had always been puzzled by the lightness of the Moon. They had speculated on it as being mainly pumice. Lately there had been much speculation and opinion holding forth the theory that the Moon was porous, had these bubbles and air pockets all through it, that the Moon's water and atmosphere had all gone underground to be sealed off in these hollow spaces. He now knew they were right.

Most of these Moon bubbles, large enough to hold cities, must be entirely sealed off. But others were linked, sometimes broken into by quakes or the volcanic action which was still going on in the depths of what had once been considered a dead world. This particular cavern was such a bubble.

Robin walked along the outer wall and saw a dark black spot in it, and then others. He came to them, found they were breaks in the surface, pocks caused by smaller bubbles. He looked into one that opened at the base. Using his flashlight, he could see that it was a small, almost entirely spherical cave. He found others pocking the walls of the cavern bubble.

This then was the ideal spot for a permanent home. Not that he needed shielding from the elements, for obviously there were no elements here—no rain, snow, clouds, or weather oddities. Neither was there night or day.

Robin would move his possessions into this cave, simply to have them located and safe. Besides, there might be some larger form of life, some carnivores around—he could not tell. Better to be safe than sorry, he said to himself.

He acted at once, carrying the rocket nose and its stuff to the cave, transferring his rabbits and their pen to a spot just outside the cave door. He would need a bowl for water and, using his screwdriver blade, he finally managed to detach the curved rocket nose and found himself in possession of a deep bowl. He took this down to the water, filled it and carried it back to his cave.

Already he began to feel cheerier. Nothing like work, he thought, to take your mind off your other problems. Suddenly he realized he was tired.

How long had he been at this? He did not know. Now he realized that with no sunrise or sunset visible in his underground world, he could not tell time. He looked at his wrist watch, but it had stopped running, of course. He decided to take a nap; he lay down and fell asleep.

When he woke up, he set his watch at eight o'clock, decided to consider this the beginning of a day. He found the notebook he'd carried in his back pocket, opened it, and set up his new calendar. Using the date of the rocket's take-off, he allowed five days as a probable estimate of the time passed since. He had no means of knowing how long he had been ill, he suspected it had been longer, but decided to let it stand. After arriving at the date, he made the time eight in the morning, laid out the times he expected to eat, to work, to sleep. He would try to live according to a full Terrestrial day, checking the passage of time by his watch.

He then listed all the things he expected would have to be done, and decided to check them off as he completed them. Next he ate breakfast from the fruit of the ball-tree. He spent the rest of that morning trying to find a means of making fire. He had some bits of steel from the rocket, and he tried to strike sparks on everything that resembled rock. After a search, he found some fragments of rock near the water that gave off a spark. Whether these were flints or not, he did not care, so long as they worked for him.

With this discovery he knew he would be free from worry about the problem of matches. His next problem was to secure a weapon. This solved itself rather fast with a bow and arrow. A long, flexible metal tube from the rear connections of the rocket, bent to make a bow when tied with a string of nylon cord, made a satisfactory twang when pulled. He made arrows out of the fibers of the Moontree stalks, and practiced shooting.

The next few days followed the same pattern. Robin enlarged his area of exploration, finding several other kinds of Lunar vegetation and a number of other insect-worms. He found several that were quite large, one as large as a squirrel. It was an odd thing, humping itself along in little bounds—a creature of a dozen ball-like segments, two of which had toothed mouths, although only the ball in front had an eye, a lidless orb set in the center of this ball. But the creature was fringed with the light-rod organs as the tiny worm-ants had been.

Robin tried to cook part of this creature but the monkey refused to touch it and he found it entirely unpalatable. On the other hand, he found that when he removed the little yellow balls from the top of the light stalks on the creature, they remained glowing—even as do the abdomens of fireflies. He therefore diligently set about catching a number of these Moonrats, as he named them, and making a lantern for himself by filling a glass tube with the glow organs. This worked out quite nicely when he experimented in his dark cave-home, emitting a clear, though pale, yellow light.

His rabbit had a nice litter at last, and Robin carefully saw that they were kept well supplied with food and drink. He would eat no more meat until there were several dozen adults, all breeding. But he felt that now he was assured of a source of clothing when his own would give out. He knew that eventually he would have to dress himself entirely in the products of his own ingenuity. His Earth clothes could last no more than a few years. He had already devised for himself an experimental pair of sandals from the rinds of the ball-tree fruit and the stalks of the Moontrees. They would do, and he carefully removed his shoes and put them away. When he had heavy exploring to do, or if and when he might try to reach the surface, he would need his good heavy leather shoes. Until then, the makeshift sandals would do.

For he knew that someday he would have to reach the surface. If and when the first astronauts arrived, they would not go below. They would probably never suspect the presence of these unseen areas beneath the crust, possibly not for many dozens of years. It would be on the surface that Robin would have to go to find rescue. That was the greatest problem he would have to solve. Against that terrible trip, he would have to conserve and plan.

Meanwhile, he had a toehold on life here, if conditions within his sublunar cavern did not change. But they were changing ... and not for the better.