“Another point. As you will have noticed, it’s become rather warm, and will continue to do so for some time. Therefore I advise you to take off all unnecessary clothing; comfort is much more important than modesty.” (And survival, he added silently, is much more important than comfort–but it would be some hours yet before it came to that.)
“We’ll turn off the main cabin lights, but since we don’t want to be in complete darkness, we’ll leave on the emergency lighting at low power. One of us will remain on watch at all times in the skipper’s seat. Mr. Harris is working out a roster of two-hour shifts. Any questions or comments?”
There were none, and the Commodore breathed a sigh of relief. He was afraid that someone would be inquisitive about the rising temperature, and was not quite sure how he would have answered. His many accomplishments did not include the gift of lying, and he was anxious that the passengers should have as untroubled a sleep as was possible in the circumstances. Barring a miracle, it would be their last.
Miss Wilkins, who was beginning to lose a little of her professional smartness, took round final drinks for those who needed them. Most of the passengers had already begun to remove their outer clothing; the more modest ones waited until the main lights went off. In the dim red glow, the interior of _Selene_ now had a fantastic appearance, One that would have been utterly inconceivable when she left Port Roris a few hours before. Twenty-two men and women, most of them stripped down to their underclothing, lay sprawled across the seats or along the floor. A few lucky ones were already snoring, but for most, sleep would not come as easily as that.
Captain Harris had chosen a position at the very rear of the cruiser; in fact, he was not in the cabin at all, but in the tiny air-lock galley. It was a good vantage point. Now that the communicating door had been slid back, he could look the whole length of the cabin and keep an eye on everyone inside it.
He folded his uniform into a pillow, and lay down on the unyielding floor. It was six hours before his watch was due, and he hoped he could get some sleep before then.
Sleep! The last hours of his life were ticking away, yet he had nothing better to do. How well do condemned men sleep, he wondered, in the night that will end with the gallows?
He was so desperately tired that even this thought brought no emotion. The last thing he saw, before consciousness slipped away, was Dr. McKenzie taking yet another temperature reading and carefully plotting it on his chart, like an astrologer casting a horoscope.
Fifteen meters above–a distance that could be covered in a single stride under this low gravity–morning had already come. There is no twilight on the Moon, but for many hours the sky had held the promise of dawn. Stretching far ahead of the sun was the glowing pyramid of the zodiacal light, so seldom seen on Earth. With infinite slowness it edged its way above the horizon, growing brighter and brighter as the moment of sunrise approached. Now it had merged into the opalescent glory of the corona; and now, a million times more brilliant than either, a thin thread of fire began to spread along the horizon as the sun made its reappearance after fifteen days of darkness. It would take more than an hour for it to lift itself clear of the sky line, so slowly did the Moon turn on its axis, but the night had already ended.
A tide of ink was swiftly ebbing from the Sea of Thirst, as the fierce light of dawn swept back the darkness. Now the whole drab expanse of the Sea was raked with almost horizontal rays. Had there been anything showing above its surface, this grazing light would have thrown its shadow for hundreds of meters, revealing it at once to any who were searching.
But there were no searchers there. Duster One and Duster Two were busy on their fruitless quest in Crater Lake, fifteen kilometers away. They were still in darkness; it would be another two days before the sun rose above the surrounding peaks, though their summits were already blazing with the dawn. As the hours passed, the sharp-edged line of light would creep down the flanks of the mountains–sometimes moving no faster than a man could walk–until the sun climbed high enough for its rays to strike into the crater.
But man-made light was already shining there, flashing among the rocks as the searchers photographed the slides that had come sweeping silently down the mountains when the Moon trembled in its sleep. Within an hour, those photographs would have reached Earth; in another two, all the inhabited worlds would have seen them.
It would be very bad for the tourist business.
When Captain Harris awoke, it was already much hotter. Yet it was not the now oppressive heat that had interrupted his sleep, a good hour before he was due to go on watch.
Though he had never spent a night aboard her, Pat knew all the sounds that _Selene_ could make. When the motors were not running, she was almost silent; one had to listen carefully to notice the susurration of the air pumps and the low throb of the cooling plant. Those sounds were still there, as they had been before he went to sleep. They were unchanged; but they had been joined by another.
It was a barely audible whisper, so faint that for a moment he could not be sure he was not imagining it. That it should have called to his subconscious mind across the barriers of sleep seemed quite incredible. Even now that he was awake, he could not identify it, or decide from which direction it came.
Then, abruptly, he knew why it had awakened him. In a second, the sogginess of sleep had vanished. He got quickly to his feet, and pressed his ear against the air-lock door, for that mysterious sound was coming, from _outside_ the hull.
Now he could hear it, faint but distinct, and it set his skin crawling with apprehension. There could be no doubt; it was the sound of countless dust grains whispering past _Selene’s_ walls like a ghostly sandstorm. What did it mean? Was the Sea once more on the move? If so, would it take _Selene_ with it? Yet there was not the slightest vibration or sense of motion in the cruiser itself; only the outside world was rustling past.
Very quietly, being careful not to disturb his sleeping companions, Pat tiptoed into the darkened cabin. It was Dr. McKenzie’s watch. The Scientist was hunched up in the pilot’s seat, staring out through the blinded windows. He turned round as Pat approached, and whispered: “Anything wrong at your end?”
“I don’t know–come and see.”
Back in the galley, they pressed their ears against the outer door, and listened for a long time to that mysterious crepitation. Presently McKenzie said: “The dust’s moving, all right– but I don’t see why. That gives us another puzzle to worry about.”
“Another?”
“Yes. I don’t understand what’s happening to the temperature. It’s still going up, but nothing like as fast as it should.”
The physicist seemed really annoyed that his calculations had proved incorrect, but to Pat this was the first piece of good news since the disaster.
“Don’t look so miserable about it; we all make mistakes. And if this one gives us a few more days to live, I’m certainly not complaining.”
“But I _couldn’t_ have made a mistake. The math is elementary. We know how much heat twenty-two people generate, and it must go somewhere.”
“They won’t produce so much heat when they’re sleeping; maybe that explains it.”
“You don’t think I’d overlook anything so obvious as that!” said the scientist testily. “It helps, but it isn’t enough. There’s some other reason why we’re not getting as hot as we should.”
“Let’s just accept the fact and be thankful,” said Pat. “Meanwhile, what about this noise?”
With obvious reluctance, McKenzie switched his mind to the new problem.
“The dust’s moving, but we aren’t, so it’s probably merely a local effect. In fact, it only seems to be happening at the back of the cabin. I wonder if that has any significance.” He gestured to the bulkhead behind them. “What’s on the other side of this?”
“The motors, oxygen reserve, cooling equipment . . .”
“_Cooling_ equipment! Of course! I remember noticing that when I came aboard. Our radiator fins are back there, aren’t they?”
“That’s right.”
“_Now_ I see what’s happened. They’ve got so hot that the dust is circulating, like any liquid that’s heated. There’s a dust fountain outside, and it’s carrying away our surplus heat. With any luck, the temperature will stabilize now. We won’t be comfortable, but we can survive.”