There went number three, its last section moving with almost imperceptible slowness. But it was still moving; in a few minutes, with any luck at all, they would be knocking on the cruiser’s roof.
“Twelve meters down,” said Lawrence. “We’re only three meters above you now, _Selene_. You should be able to hear us at any minute.”
Indeed they could, and the sound was wonderfully reassuring. More than ten minutes ago Hansteen had noticed the vibration of the oxygen inlet pipe as the caisson scraped against it. You could tell when it stopped, and when it started moving again.
There was that vibration once more, accompanied this time by a delicate shower of dust from the roof. The two air pipes had now been drawn up so that about twenty centimeters of their lengths projected through the ceiling, and the quickdrying cement which was part of the emergency kit of all space vehicles had been smoothed around their points of entry. It seemed to be working loose, but that impalpable rain of dust was far too slight to cause alarm. Nevertheless, Hansteen thought that he had better mention it to the skipper, who might not have noticed.
“Funny,” said Pat, looking up at the projecting pipe. “That cement should hold, even if the pipe is vibrating.”
He climbed up on a seat, and examined the air pipe more closely. For a moment he said nothing; then he stepped down, looking puzzled and annoyed–and more than a little worried.
“What’s the trouble?” Hansteen asked quietly. He knew Pat well enough now to read his face like an open book.
“That pipe’s pulling up through the roof,” he said. “Someone up on the raft’s being mighty careless. It’s shortened by at least a centimeter, since I fixed that plaster.” Then Pat stopped, suddenly aghast. “My God,” he whispered, “suppose it’s our own fault, _suppose we’re still sinking_.”
“What if we are?” said the Commodore, quite calmly. “You’d expect the dust to continue settling beneath our weight. That doesn’t mean we’re in danger. Judging by that pipe, we’ve gone down one centimeter in twenty-four hours. They can always give us some more tubing if we need it.”
Pat laughed a little shamefacedly.
“Of course–that’s the answer. I should have thought of it before. We’ve probably been sinking slowly all the time, but this is the first chance we’ve had to prove it. Still, I’d better report to Mr. Lawrence–it may affect his calculations.”
Pat started to walk toward the front of the cabin; but he never made it.
Chapter 25
It had taken Nature a million years to set the trap that had snared _Selene_ and dragged her down into the Sea of Thirst. The second time, she was caught in a trap that she had made herself.
Because her designers had no need to watch every gram of excess weight, or plan for journeys lasting more than a few hours, they had never equipped _Selene_ with those ingenious but unadvertised arrangements whereby spaceships recycle all their water supply. She did not have to conserve her resources in the miserly manner of deep-space vehicles; the small amount of water normally used and produced aboard, she simply dumped.
Over the past five days, several hundred kilos of liquid and vapor had left _Selene_, to be instantly absorbed by the thirsty dust. Many hours ago, the dust in the immediate neighborhood of the waste vents had become saturated and had turned into mud. Dripping downward through scores of channels, it had honeycombed the surrounding Sea. Silently, patiently, the cruiser had been washing away her own foundations. The gentle nudge of the approaching caisson had done the rest.
Up on the raft, the first intimation of disaster was the flashing of the red warning light on the air purifier, synchronized with the howling of a radio klaxon across all the space-suit wave bands. The howl ceased almost immediately, as the technician in charge punched the cutoff button, but the red light continued to flash.
A glance at the dials was enough to show Lawrence the trouble. The air pipes–_both_ of them–were no longer connected to _Selene_. The purifier was pumping oxygen into the Sea through one pipe and, worse still, sucking in dust through the other. Lawrence wondered how long it would take to clean out the filters, but wasted no further time upon that thought. He was too busy calling _Selene_.
There was no answer. He tried all the cruiser’s frequencies, without receiving even a whisper of a carrier wave. The Sea of Thirst was as silent to radio as it was to sound.
They’re finished, he said to himself; it’s all over. It was a near thing, but we just couldn’t make it. And all we needed was another hour.
What could have happened? he thought dully. Perhaps the hull had collapsed under the weight of the dust. No–that was very unlikely; the internal air pressure would have prevented that. It must have been another subsidence. He was not sure, but he thought that there had been a slight tremor underfoot. From the beginning he had been aware of this danger, but could see no way of guarding against it. This was a gamble they had all taken, and _Selene_ had lost.
Even as _Selene_ started to fall, something told Pat that this was quite different from the first cave-in. It was much slower, and there were scrunching, squishing noises from outside the hull which, even in that desperate moment, struck Pat as being unlike any sounds that dust could possibly make.
Overhead, the oxygen pipes were tearing loose. They were not sliding out smoothly, for the cruiser was going down stern first, tilting toward the rear. With a crack of splintering Fiberglas, the pipe just ahead of the air-lock galley ripped through the roof and vanished from sight. Immediately, a thick jet of dust sprayed into the cabin, and fanned out in a choking cloud where it hit the floor.
Commodore Hansteen was nearest, and got there first. Tearing off his shirt, he swiftly wadded it into a ball and rammed it into the aperture. The dust spurted in all directions as he struggled to block the flow. He had almost succeeded when the forward pipe ripped loose-and the main lights went out as, for the second time, the cable conduit was wrenched away.
“I’ll take it!” shouted Pat. A moment later, also shirtless, he was trying to stem the torrent pouring in through the hole.
He had sailed the Sea of Thirst a hundred times, yet never before had he touched its substance with his naked skin. The gray powder sprayed into his nose and eyes, half choking and wholly blinding him. Though it was as bone dry as the dust from a Pharaoh’s tomb–dryer than this, indeed, for it was a million times older than the pyramids–it had a curiously soapy feeling. As he fought against it, Pat found himself thinking: If there is one death worse than being drowned, it’s being buried alive.
When the jet weakened to a thin trickle, he knew that he had avoided that fate-for the moment. The pressure produced by fifteen meters of dust, under the low lunar gravity, was not difficult to overcome-though it would have been another story if the holes in the roof had been much larger.
Pat shook the dust from his head and shoulders, and cautiously opened his eyes. At least he could see again; thank heaven for the emergency lighting, dim though it was. The Commodore had already plugged his leak, and was now calmly sprinkling water from a paper cup to lay the dust. The technique was remarkably effective, and the few remaining clouds quickly collapsed into patches of mud.
Hansteen looked up and caught Pat’s eye.
“Well, Captain,” he said. “Any theories?”
There were times, thought Pat, when the Commodore’s Olympian self-control was almost maddening. He would like to see him break, just once. No-that was not really true. His feeling was merely a flash of envy, even of jealousy–understandable, but quite unworthy of him. He should be ashamed of it, and he was.
“I don’t know _what’s_ happened,” he said. “Perhaps the people on top can tell us.”
It was an uphill walk to the pilot’s position, for the cruiser was now tilted at about thirty degrees from the horizontal. As Pat took his seat in front of the radio, he felt a kind of despairing numbness that surpassed anything he had known since their original entombment. It was a sense of resignation, an almost superstitious belief that the gods were fighting against them, and that further struggle was useless.
He felt sure of this when he switched on the radio and found that it was completely dead. The power was off; when that oxygen pipe had ripped out the roof cable conduit, it had done a thorough job.
Pat swiveled slowly around in his seat. Twenty-one men and women were looking at him, awaiting his news. But twenty of them he did not see, for Sue was watching him, and he was conscious only of the expression on her face. It held an anxiety and readiness–but, even now, no hint of fear. As Pat looked at her, his own feelings of despair seemed to dissolve. He felt a surge of strength, even of hope.