There was nothing he could do to shorten that five minutes; the whole plan depended upon the foam setting to a known consistency. If his timing and positioning had been faulty, or the chemists back at Base had made an error, the people aboard _Selene_ were already as good as dead.
He used the waiting period to tidy up the shaft, sending all the equipment back to the surface. Soon only Lawrence himself was left at the bottom, with no tools at all but his bare hands. If Maurice Spenser could have smuggled his camera into this narrow space–and he would have signed any reasonable contract with the Devil to have done so-his viewers would have been quite unable to guess Lawrence’s next move.
They would have been still more baffled when what looked like a child’s hoop was slowly lowered down the shaft. But this was no nursery toy; it was the key that would open _Selene_.
Sue had already marshaled the passengers to the front–and now much higher–end of the cabin. They were all standing there in a tightly packed group, looking anxiously at the ceiling and straining their ears for every encouraging sound.
Encouragement, thought Pat, was what they needed now. And he needed it more than any of them, for he alone knew– unless Hansteen or McKenzie had guessed it–the real magnitude of the danger they were facing.
The fire was bad enough, and could kill them if it broke through into the cabin. But it was slow-moving, and they could fight it, even if only for a while. Against explosion, however, they could do nothing.
For _Selene_ was a bomb, and the fuse was already lit. The stored-up energy in the power cells that drove her motors and all her electrical devices could escape as raw heat, but it could not detonate. That was not true, unfortunately, of the liquidoxygen tanks.
They must still hold many liters of the fearfully cold, violently reactive element. When the mounting heat ruptured those tanks, there would be both a physical and a chemical explosion. A small one, it was true–perhaps equivalent to a hundred kilograms of T.N.T. But that would be quite enough to smash _Selene_ to pieces.
Pat saw no point in mentioning this to Hansteen, who was already planning his barricade. Seats were being unscrewed from the rows near the front of the cabin, and jammed between the rear row and the toilet door. It looked as if the Commodore was preparing for an invasion rather than a fire– as indeed he was. The fire itself, because of its nature, might not spread beyond the power-cell compartment, but as soon as that cracked and blistered wall finally gave way, the dust would come flooding through.
“Commodore,” said Pat, “while you’re doing this, I’ll start organizing the passengers. We can’t have twenty people trying to get out at once.”
That was a nightmare prospect that had to be avoided at all costs. Yet it would be hard to avoid panic–even in this welldisciplined community–if a single narrow tunnel was the only means of escape from a rapidly approaching death.
Pat walked to the front of the cabin; on Earth that would have been a steep uphill climb, but here a thirty-degree slope was barely noticeable. He looked at the anxious faces ranged in front of him and said: “We’re going to be out of here very soon. When the ceiling opens, a rope ladder will be dropped down. The ladies will go first, then the men–all in alphabetical order. Don’t bother to use your feet. Remember how little you weigh here, and go up hand over hand, as quickly as you can. But don’t crowd the person in front; you should have plenty of time, and it will take you only a few seconds to reach the top.
“Sue, please sort everyone out in the right order. Harding, Bryan, Johanson, Barrett–I’d like you to stand by as you did before. We may need your help-”
He did not finish the sentence. There was a kind of soft, muffled explosion from the rear of the cabin–nothing spectacular; the popping of a paper bag would have made more noise. But it meant that the wall was down–while the ceiling, unfortunately, was still intact.
On the other side of the roof, Lawrence laid his hoop flat against the Fiberglas and started to fix it in position with quick-drying cement. The ring was almost as wide as the little well in which he was crouching; it came to within a few centimeters of the corrugated walls. Though it was perfectly safe to handle, he treated it with exaggerated care. He had never acquired that easy familiarity with explosives that characterizes those who have to live with them.
The ring charge he was tamping in place was a perfectly conventional specimen of the art, involving no technical problems. It would make a neat clean out of exactly the desired width and thickness, doing in a thousandth of a second a job that would have taken a quarter of an hour with a power saw. That was what Lawrence had first intended to use; now he was very glad that he had changed his mind. It seemed most unlikely that he would have a quarter of an hour.
How true that was, he learned while he was still waiting for the foam to set. “The fire’s through into the cabin!” yelled a voice from overhead.
Lawrence looked at his watch. For a moment it seemed as if the second hand was motionless, but that was an illusion he had experienced all his life. The watch had not stopped; it was merely that Time, as usual, was not going at the speed he wished. Until this moment it had been passing too swiftly; now, of course, it was crawling on leaden feet.
The foam should be rock-hard in another thirty seconds. Far better to leave it a little longer than to risk shooting too soon, while it was still plastic.
He started to climb the rope ladder, without haste, trailing the thin detonating wires behind him. His timing was perfect. When he had emerged from the shaft, uncrimped the short circuit he had put for the sake of safety at the end of the wires, and connected them to the exploder, there were just ten seconds to go.
“Tell them we’re starting to count down from ten,” he said.
As Pat raced downhill to help the Commodore–though just what he could do now, he had very little idea–he heard Sue calling in an unhurried voice: “Miss Morley, Mrs. Schuster, Mrs. Williams . . .” How ironic it was that Miss Morley would once again be the first, this time by virtue of alphabetical accident. She could hardly grumble about the treatment she was getting now.
And then a second and much grimmer thought flashed through Pat’s mind. _Suppose Mrs. Schuster got stuck in the tunnel and blocked the exit_. Well, they could hardly leave her until last. No, she’d go up all right; she had been a deciding factor in the tube’s design, and since then she had lost several kilos.
At first glance, the outer door of the toilet still seemed to be holding. Indeed, the only sign that anything had happened was a slight wisp of smoke curling past the hinges. For a moment Pat felt a surge of relief; why, it might take the fire half an hour to burn through the double thickness of Fiberglas, and long before that–
Something was tickling his bare feet. He had moved automatically aside before his conscious mind said, “_What’s that?_”
He looked down. Though his eyes were now accustomed to the dim emergency lighting, it was some time before he realized that a ghostly gray tide was pouring beneath that barricaded door–and that the panels were already bulging inward under the pressure of tons of dust. It could be only a matter of minutes before they collapsed; even if they held, it might make little difference. That silent, sinister tide had risen above his ankles even while he was standing here.
Pat did not attempt to move, or to speak to the Commodore, who was standing equally motionless a few centimeters away. For the first time in his life–and now, it might well be, for the last–he felt an emotion of sheer, overwhelming hate. In that moment, as its million dry and delicate feelers brushed against his bare legs, it seemed to Pat that the Sea of Thirst was a conscious, malignant entity that had been playing with them like a cat with a mouse. Every time, he told himself, we thought we were getting the situation under control, it was preparing a new surprise. We were always one move behind, and now it is tired of its little game; we no longer amuse it. Perhaps Radley was right, after all.
The loud-speaker dangling from the air pipe roused him from his fatalistic reverie.