Keeping a sharp eye out, Harry advanced step by step to the very threshold of the cave. Deep inside, thirty or forty meters ahead, the discreet lights that he had noticed earlier still burned, making modest pools of illumination in front of and around mysterious equipment whose purpose the intruder could not yet guess. The moaning sounds were coming from somewhere in the same vicinity.

Harry's view of the area was partially blocked by squarish intervening objects, and he saw that he was facing the back of a row of high crates and cabinets that formed a rough partition across most of the width of the cave.

The pummeling Harry's armor had absorbed from falling rocks and glancing shots had started up some stray vibrations in his suit so that the arms and legs were taking turns in palsied quiverings. Inside his helmet and its forcefield pads, his ears still rang. He hoped and expected that, given a little time, his gear could readjust itself to deal with these several problems. Meanwhile, he could still see and hear and walk. He could fire the carbine again if he had to. He only hoped he could still hit something.

It was almost as if his quivering suit had suddenly turned coward on him. Before turning his back on what was left of the berserker, Harry instinctively gave the ruin one more careful look, just making sure the bits and pieces were now harmless. In the past he had seen the damned berserkers do too many wonderful and horrible things to ever feel safe in the presence of one of them, even when it had been torn apart. Maybe after the remains had been thoroughly gone over by human experts and their tools, and then mounted in a museum for about a year. And even then Harry thought he would be cautious.

Before advancing any farther, he also glanced once more at each of the fallen Templars. No, there wasn't any doubt. They were both as dead as the berserker.

Having got in a few meters under the cave's roof, Harry paused, aware that he needed a breathing space, just to pull himself together. Automatically he ran a checklist on his suit and weapon and felt reasonably satisfied with the result. The vibrations were slowly damping down. He didn't need to take a fresh look at himself to know that the surface of his armor must be freshly scorched and scarred, and he thought it might be still glowing red in one place on his back. His helmet's small statglass faceplate, in nearly pristine condition when this little skirmish started, was going to need replacement before it took another shot.

But he had to give the lights and the equipment in the cave at least one quick look before he took time out for maintenance. One look, and then get right back to the Witch.

Meanwhile the sounds of breathing still kept on, indicating that someone else was still alive. Unless they were being made by some kind of recording, and that seemed stupid. If there was some living victim who could be rescued, that would be fine. But something more than that was driving Harry now, pushing him deeper into the cave: the nagging thought that if one of the berserkers' fighting machines had been programmed to do nothing but guard this place, then its contents must be of great importance to the enemy, might offer some means by which the death machines could be seriously hurt.

Very rarely would the damned machines keep anyone alive. They always needed some especially bad reason for doing so. But the human whose lungs now labored up ahead was someone the berserkers wanted to keep breathing. Or, alternatively, it was only some wounded goodlife, whose metal masters had not yet got around to finishing off their faithful but worn-out servant.

Or there could be a third scenario: the sentry machine had been unable to leave its post for even a few seconds, the time it would have taken to go deeper into the cave and kill the stubborn breather off.

All three possibilities were interesting. Maybe, Harry thought, if a berserker's directing unit awarded it points for every death achieved, not many would be handed out for terminating a life that was almost over anyway.

Harry was moving again, stepping slowly and carefully, looking out in all directions for possible booby traps. He was well aware that there could also be some lurking berserker auxiliary machine, designed for something other than direct combat, but still ready to take a whack at any creature that moved and breathed and happened to come in range. Or there might be yet another goodlife here, one who wasn't dead or dying. Yes, there were all sorts of interesting possibilities.

Harry had reached the crude partition of crates and cabinets, and was passing through a gap in the uneven barrier. A standard, plain, plastic-paneled cabinet, doubtless housing a small hydrogen power lamp, stood against one of the cave's side walls. Just a piece of furniture you might see almost anywhere, in a mine or a home or a simple office. Just an ordinary power source keeping various kinds of equipment going, including a few modest electric lights that it seemed no one had bothered to turn off.

Having come this far, Harry could see that the illuminated portion of the cavern went back a long way, much farther than he would have guessed, maybe a hundred meters or even more. The surface of the rock in the remoter sections had a raw, shaved look, as if someone or something had worked on it intensively, sculpting what had begun as a natural fissure of some kind into a secret tunnel.

Already the land had begun the process of natural smoothing, almost healing, that seemed to follow any artificial deformation on this world. The final result was a tunnel of uniform diameter, wide enough to accommodate something even bigger than a pedicar, maybe half the diameter of Harry's Witch. Harry had to assume that the whole length of the tunnel lay in a free zone, for heavy, modern mining machinery must have been at work. Whoever or whatever had done the digging must have moved tons and tons of the fabric of Maracanda. Doubtless they had dumped the debris down a crevice somewhere, as there hadn't been any huge pile outside the cave.

Harry's sensitive airmikes were now beginning to pick up, along with the breathing and the moans, the words of someone weakly calling for help. He thought it sounded like a woman or a child, but he could not be sure.

Such of his suit's sensors as were still working informed him that, besides a human heart and lungs, several high-tech devices were still operating inside the cave. Subtle things, emitting their delicate purrs and whines. Listening carefully, Harry didn't think that any of them were actual berserkers. If another fighting machine was waiting to ambush him, he would probably never hear a thing.

He kept expecting the worst. But what he actually discovered, one after another, was a series of empty shipping containers, irregularly strewn about. He could see that a couple of them had been labeled in several places as MINING MACHINERY.

It seemed that other, similar crates had been broken up to make crude furniture. Even goodlife, Harry supposed, had to sleep somewhere, and had some use for chairs and tables.

Standing beside the electric lamp placed farthest from the entrance, he could see that at this point the new tunnel diverged from the natural cave, which here bent itself, in abrupt Maracandan fashion, diving sharply downward, beginning a precipitous descent to unknown depths. Probably, Harry thought, the material excavated from the new tunnel had been dumped down there. From here the new passageway still drove almost straight ahead, descending only on a much gentler slope. The last electric light threw its fading radiance along the straight tunnel that went on endlessly into darkness, starting to curve down more as it went deeper and farther. Neither the fixed lamp nor Harry's suit's headlamp, which fortunately had survived the fight, could show him what lay at the end.

Harry turned his head. For just a moment he thought he heard faint, mechanical sounds, coming from somewhere down the tunnel.

The sound was not repeated. Anyway, he had an investigation near at hand that might be more important. The sound of ragged human breathing, mixed with an occasional moan for help, had been growing nearer as Harry advanced. His sensitive air-mikes enabled him to close in on the sounds, and now their source must be almost within reach.

Moving warily around a machine that might have been some kind of berserker device, but demonstrated its innocence by not attempting to mangle him as he stepped past, he could see what looked like a cell, part of some primitive jail, except that it seemed too small. Actually it was only a kind of cage, fashioned in a very low-tech way from another of the surplus shipping crates. An improvised door was fastened shut with a simple lock.

Harry peered in through the slats that served as bars. Inside the small crude cell, a ragged shape stirred, a head lifted from a simple pallet on the cave floor inside the cage.

A woman's voice croaked out: "I heard the shooting. Oh, thank God, thank God. You're... human."

"Last time I checked," said Harry with his airspeaker, thinking that a lot of people, seeing him in his suit, would probably have taken him for something else. "And as badlife as they come."

"Me, too." The woman turned painfully from her side to her back, holding up her right hand as if it might be hurt. Her long hair was matted, colorless with neglect and grime; her prospector's work clothes were dirty shreds. Sunken, fearful eyes looked out of a pasty face. Her voice sounded rusty, as if from lack of use. "Are they gone?" Then: "Are you alone?"

Harry was giving the cage a quick inspection for booby traps. "They're gone, for the time being anyway. And I'm not alone now, I'm with you. Might your first name be Emily?"

The woman nodded. It was hard to even guess her age. Tears were streaking her face. "My name is Kochi. Emily Kochi."

Harry nodded. "Dr. Kochi, people have been looking for you for several months."

The cage having passed its swift inspection, Harry took hold of the slats that made the door, and broke it open, an easy task for servo-powered arms.

"Don't touch my hand!" she warned him, holding it up carefully. He could see something wrong with a couple of the fingers, a bad bending and discoloring.

"I won't." Leaning into the cage to help the prisoner out, he cautioned: "And you be careful of my armor. The outer surface may still be very hot in places."

Fortunately, the waves of stray vibrations in the limbs of Harry's suit had run their course. By the time he had extracted Dr. Kochi from her cage, he could once again move his arms, and walk, without looking like a drunk or a case of some ancient nerve disease.

Dr. Kochi, the astrogeologist, had to crawl out of the cell to give herself room enough to stand. The victim was able to stand up, but only barely. Then she stumbled and had to lean on things. Harry gave her a drink of water after she pointed out where the supply was kept.

Presently Harry had got her moving back toward the exit from the cave, on the way to medical care. Fortunately it turned out that the front of his armor had cooled enough to touch human skin without scorching.

Meanwhile, the words, the revelations, once started came pouring out. Dr. Kochi was eager to start telling someone things she deemed of great, of terrible importance.

In her haste and confusion, the revelations came out only gradually, in the form of disconnected details. Slowly Harry was getting the picture, of some murderous plot created by the berserkers and their goodlife helpers.

Turning back toward the glow of daylight from the cave's mouth, taking what seemed a more direct route past the barrier of crates and boxes, Harry's attention was caught by a kind of mockup or simulation of the infernal device the bad machines were trying to create.

Not wanting to delay by even a few seconds, Harry paused only momentarily to look at the holostage model. Clearly it was a representation of Maracanda itself, revolving slowly in space.

The woman's voice was soft and weak. "This was for the goodlife to watch, you see. To inspire them. So the machine could show them what they were working toward, they could understand what the berserkers were trying to accomplish. One of those - those people - wanted to broadcast it somehow to all the people on Maracanda, once it was too late. So the people on Maracanda could understand, before they died, how many billions of others were going to die with them."

The images on the holostage abruptly shifted. Now the presentation was of another model, this one obviously representing the tripartite Maracandan system. One spot of ebony, backlighted with a flickering glow, plainly symbolized the black hole Ixpuztec, and a metallic-looking sphere, fringed with infalling radiance, was standing in for Avalon, the neutron star.

The trouble was that at first Harry couldn't make much sense out of it. Something about a great explosion.

The woman's vast relief at finding herself still alive, at being rescued, was turning into a new panic. The next thing she said was: "Somebody's got to do something. Interfere somehow and stop them."

"Slow down. Take it easy. It'll be all right now. What're you talking about? Where? Stop them from doing what?"

"Blowing up the world. This whole solar system." She paused a moment to take a breath, and then hit Harry with a stunner. "But that's only the start. Turning the pulsar into a hypernova. Within a hundred light-years there are a hundred inhabited systems, and they'll all be fried."

Harry stopped dead, thinking about that statement. He could only hope it was delirium. In a moment he had picked up Dr. Kochi, gently, and was carrying her at a brisk walk. "Come along. I'm going to get you back to my ship." He shifted her slightly in his arms, giving himself room to use the carbine if he had to.

"No, listen to me! I'm not crazy, I'm not!" She beat with her good hand on his armored chest. "I don't know if it'll work, this thing they're trying to do. But I'm afraid it might."

More words poured out, most of them making sense. She had been kidnapped while working alone out in the field, trying to discover the properties, fathom the nature, of breakdown zones, with a view to ultimately being able to do away with them. Or recreate them, in free space, as weapons and shields.

The people who kidnapped her had shown themselves to be strange, crazy villains, and when she had realized that they were goodlife, she had realized there would be no ransom, had given up hope of ever getting away from them alive. They served a machine, a terrible machine with a squeaking voice, that dwelt in this cave, and had asked her questions. The fact that it was not of human shape had only made it worse somehow.

But that was not exactly the kind of work the berserkers had wanted her to do for them.

Harry was jarred back into giving her his full attention. He had been fixated on what a neat weapon a breakdown zone would make if you could only throw it at your enemy. Find some way to get a berserker entangled in one.

"Then what?" he demanded.

"They wanted to know everything... about the interior of Maracanda. All about the subsurface layers of this world. Not the really deep ones. Maybe a hundred meters down. Before the dimensions really start to - go crazy. Oh, can I have more water, please?"

A pause for a swallow. "What they really focused on... There are deposits of antimatter down there. Ten, twenty metric tons sometimes, in one lump. Maybe even more. Shielded in magnetic pockets. Objects that just can't exist in our universe anywhere but here."

"Go on."

"They wanted to know how to excavate a lump of antimatter, bring it out intact, without inducing a landfall or an explosion. You might only have a half second's warning - without upsetting the balance of forces, and being crushed by ten thousand gravities. Above all, how it might be possible to dig one of those lumps out."

Meanwhile, Dr. Kochi kept on trying to explain things to Harry, elaborating on what she knew of the berserker plan. She was probably garbling some of it, and there was more that Harry couldn't have grasped even sitting in a classroom. But enough, more than enough, was coming through. The woman hadn't spoken half a dozen more sentences before Harry began to run, sweating anew inside his armor. Maybe this woman was crazy, but on the other hand maybe she was not. He had to get back to his ship.

Dr. Kochi was weeping in his arms. "I talked, I told them everything they wanted to hear. Gave them the right numbers, told them what computations to run on their computers. I couldn't help myself." As she neared the end of her story, the woman raised a quivering, grayish hand, to show Harry where the berserker, using irresistible strength and great delicacy of touch, had slowly torn out two of her fingernails.

"That's all over now. No one's blaming you for anything you told them." Harry certainly wasn't. He had seen what the bad machines could do to people, in their businesslike uncaring way, when they wanted information.

The berserker had conducted its own interrogation, ruthlessly and without wasting words. Skills gained in centuries of experience with human prisoners, knowledge passed on from one machine to another over the centuries, were efficiently brought to bear on this one.

"How come they left you still alive?"

"They told me there was only one reason. They still thought they might have to ask me more questions. One of the goodlife spelled that out for me. If their project didn't work on the first try. And there were things they were going to do to me, if it turned out I had been lying to them." The woman sobbed, and her voice changed. "But I didn't lie to them, I couldn't, I didn't have the guts. It told me that - that if I didn't tell - it would do something that would be much worse."

"That's all right, never mind that now. Meanwhile, we're on our way out of here. Before any of them come back."

"If their plan is working, they won't be coming back. But hurry, hurry anyway!"

Urgently Harry demanded of Dr. Kochi: "How much time do we have to stop them?"

"I don't know."

"How long ago did the berserkers leave you?"

But the prisoner couldn't say, with any accuracy. Her best guess was that it had probably been a couple of days ago. The machines and their helpers expected that the work of extracting the antimatter bundle from its natural site deep underground, and getting it out into space, would take at least a couple of days.

She was obviously in pain, faint and drifting in and out of consciousness, and Harry thought she might be feverish from an infection. There was no way she could tell the actual time when the enemy team of machines and humans had left the cave, taking their newly constructed space vessel with them. She had seen them pushing it along into the new tunnel, on some kind of improvised rails.

Her weak voice whispered on. "One of the goodlife wanted to go with it, ride it out into space, and right into the neutron star. But the machine said that wasn't going to be allowed."

"Yeah, yeah. Listen, Dr. Kochi - so it's possible that they could be launching this thing right now?"

The woman rolled her head from side to side. "That's what I'm trying to tell you. I'm afraid they are."

Harry was trying to be comforting. "Even if the radius of destruction from the supernova extended out for a hundred light-years, people would have years of warning. Decades of time to evacuate most of those planets - "

The woman drew in her breath sharply. "No. No, you don't understand. You don't know what a hypernova means."

Harry was calling ahead to his ship, telling Lily and the Witch to get the medirobot ready.