'Except during brief eclipses, half the external surface of this body is always in sunlight, half in the darkness and cold of space. The temperature differentials on the surface must be very large. It is a problem and an opportunity in all space-engineering.'
'Yes. I see what you mean. That would give unlimited electrical power for tunnelling robots. They could extract and refine fuel.'
'It would not, perhaps, take much to keep the engines simply ticking over.'
'Would Protectors think like that?'
'I cannot know how Protectors would think. They are more like you than me. But I sense there is power here. This asteroid was overlooked for mining because its metallic content is relatively low. But I would guess it was metal-rich when the Protectors chose to make it a spaceship. I guess some automated or natural variety of mining worm has been tunnelling and mining in it for a long time.'
'A machine refining its own ore and making its own replacement parts,' said Dimity. 'We have nothing outside fiction that can do that for so long or on such a scale. Self-sustaining machinery, processes still carrying on after a million years. And we have no information that Cybernetics was a Protector talent.'
'Obviously, they could have set themselves to acquire such a talent. Dimity, this gives us a glimpse of what mature Protector technology can do! I do not like it… And look! There are lights. They could be solar-powered engines ticking over. Or powered by long-lived fission or fusion processes. Doing essential maintenance, ready to set off a fusion reaction when needed. There are many ways hydrogen could be collected and stored, for example. Or perhaps it has been completely closed down and our Protector and Chorth-Captain have reactivated it.'
'It is as well, as you say,' said Dimity, 'that this moon was not properly explored before the end of the war. It could have been a super-weapon.'
'It still could be. I do not know if we should approach anything critical too closely. It may provoke a response.'
'I think we have to provoke a response. The status quo does not favor us.'
Dimity stepped forward cautiously. She gave a cry of fear and surprise. Vaemar leapt, grabbed her with one arm and pulled her back. Then he advanced cautiously and pointed. 'Nothing to fear too much. An active kzin gravity-sled. Heavy-duty Naval model. Chorth-captain must have brought it here. We can avoid its field.'
'I am sorry. I am a little rattled. You can handle one, Vaemar?'
'Of course. I have flown one since I was a kit. It was one of the first things Honored Step-Sire Raargh bought when we were living in the farm country.'
'Then let us not avoid it. Let us use it.'
'To fly on? There is not much space for that.'
'To fly on and to fight with. Do you think the Protectors would let us use it? We could do great damage if we could fly. I am sure they would try to stop us.'
'Dimity, I think the God, whichever one has dominion here, has been good to us. You will have to move very quickly. I will board the sled. You will take the copilot's seat and hang on for your life, and pray that these Protectors still think like Morlock Breeders, jumping down on their enemies when they see us escaping. Now!'
Vaemar and Dimity leapt into the sled. From above, two Protectors sprang. As they did so, Vaemar's claws flashed at the sled's controls, flinging its motor into maximum reverse flux. The Protectors, directly above it, were flung straight up. One smashed into the machinery above them, and stuck among it, the other, as though swimming through air, reached the edge of the field and fell onto the sled. It clung with one hand. Vaemar had time for one slash at the hand, removing three fingers and reducing its power of purchase. Desperately he continued to slash at the leathery arm and snapping beak with the w'tsai and his claws. Dimity grabbed the flight- controls of the sled. They skimmed back along the corridor as Vaemar finally cut the Protector's grip. It changed hands. Vaemar grabbed the controls and stopped the sled, keeping the field focused on the Protector. Dimity screamed in its ear and it let go. It flew upwards, seemed to grow smaller and vanished into the blackness above.
'I hope it ends up at the center of the moon,' said Vaemar as they flew back into the first chamber. 'Half a mile from any surface. I don't think I killed it, but that will give us time, I hope, to do some real damage. If it was the last Protector. We will have to hope it was. But we cannot continue sticking our noses into the cave, unarmed, in the hope more will come out. We have been lucky so far.'
Then he asked: 'Why did you make that noise? Were you what humans call terrified? Panicked?'
'In the caves the Morlocks must have evolved and enhanced every nonvisual sense,' Dimity said. 'Particularly hearing. I thought its hearing would be specially sensitive. Sensitive enough to use against it. I wondered why the other Protector did not leap out of the Sinclair field instantly instead of pausing while the field killed it. Chorth- Captain had screamed as he pushed it in, and I think that stunned it momentarily. They must have evolved in the caves to hear the slightest sound-the rustling of insectoids, the tiny bubbling of water's meniscus rising in grains of mud. Evolution towards hearing microsounds. But with never a need to evolve a defense against too much sound. I realized that just now.'
'Dimity, you do not disappoint. Now what?'
'We can get away and do real damage at the same time.'
'How?'
'The gig has a gravity-motor.'
'Yes.
'And a reaction drive.'
'So I saw when we came here.'
'I do not need to draw you a diagram, then?'
Humans who had spoken so to kzinti before had not lived long to regret their insolence. But Vaemar sprang to the ship, Dimity following.
'We still cannot get out,' said Vaemar, as the door closed behind them. Chorth-Captain's key had worked but he punched in an electronic lock as well. Both Vaemar and Dimity had noted the locking and unlocking sequence earlier. 'You must bear with me with patience here,' said Vaemar. 'No monkey-rattling… Dimity is not rattled any more?'
'At least we have a weapon,' said Dimity. 'Let us use it.'
'Danger?'
'Hero!'
'Urrr!'
The controls were built in duplicate, in sizes to be used by either Protector or kzinti hands, and Protector hands were very similar to human. As Dimity cut in the gravity-motor, thrusting it downwards, Vaemar fired the reaction-drive. Incandescent plasma gas roared out. The ship shook, but remained balanced between the two forces.
A second was enough. At a gesture from Vaemar they killed the two drives together. Cautiously, they cleared a viewport. Nothing could be seen but blackness, with flames and points and bars of red-hot wreckage fading in it. Even with a powerful searchlight they could make out no more through the smoke for some time. When it cleared somewhat, all that they could see of the inside of the Hollow Moon about them was a charred, melted, ruin.
'We have done it, Dimity!' said Vaemar. 'We have killed at least five Protectors, though they took our weapons! Urrr!' A snarl of triumph rose in his throat.
Dimity knew instinctively not to interrupt the young kzin's rejoicing too soon. Analyzing this knowledge, as she always analyzed her reactions, she realized they could not have done what they did had there not been a psi bond of some sort between them. It did not surprise her greatly. Vaemar's Ziirgah sense was a rudimentary form of proto-telepathy which most male kzinti possessed and she knew her own brainwaves were abnormal in several ways. They had acted and planned together almost instantaneously and partly without being aware of the fact.
'Now it is a matter of getting out,' she said at length. 'The hatch above us is still closed.'
Vaemar turned to the control panel again.
'In the absence of Protectors I think I can open it from here,' he said. 'I need but a little time to study the controls. Normal procedure for a ship like this when leaving a space station is to rise on the gravity motor when the lower hatch is opened, have that close behind us and then open the upper hatch. For obvious reasons both hatches cannot be opened together.'
