At first Oliver didn't much mind the shift's work. But IR-directed cameras on the robot surveyed him as well as the shaft face, and occasional shocks from its prod reminded him to keep hustling. And in the heat and bad air, as he grew ever more famished, it soon enough became the usual desperate, painful struggle to keep to the required pace.

Time disappeared into that zone of endless agony that was the latter part of a shift. Then he heard the distant klaxon of shift's end, echoing down the shaft like a cry in a dream. He turned the key in the robot and was plunged into noiseless black, the pure absolute of Nonbeing. Too tired to try opening his third eye, Oliver started back up the shaft by feel, following the last ore car of the shift. It rolled quickly ahead of him and was gone.

In the new silence distant mechanical noises were like creaks in the rock. He measured out the shift's work, having marked its beginning on the shaft floor: eighty-nine lengths of his body. Average.

It took a long time to get back to the junction with the shaft above his. Here there was a confluence of veins and the room opened out, into an odd chamber some seven feet high, but wider than Oliver could determine in every direction. When he snapped his fingers there was no rebound at all. The usual light at the far end of the low chamber was absent. Feeling sandwiched between two endless rough planes of rock, Oliver experienced a sudden claustrophobia; there was a whole world overhead, he was buried alive.... He crouched and every few steps tapped one rail with his ankle, navigating blindly, a hand held forward to discover any dips in the ceiling.

He was somewhere in the middle of this s.p.a.ce when he heard a noise behind him. He froze. Air pushed at his face. It was completely dark, completely silent. The noise squeaked behind him again: a sound like a fingernail, brushed along the banded metal of piano wire. It ran right up his spine, and he felt the hair on his forearms pull away from the dried sweat and stick straight out. He was holding his breath. Very slow footsteps were placed softly behind him, perhaps forty feet away... an airy snuffle, like a big nostril sniffing. For the footsteps to be so s.p.a.ced out it would have to be....

Oliver loosened his joints, held one arm out and the other forward, tiptoed away from the rail, at right angles to it, for twelve feathery steps. In the lunar gravity he felt he might even float. Then he sank to his knees, breathed through his nose as slowly as he could stand to. His heart knocked at the back of his throat, he was sure it was louder than his breath by far. Over that noise and the roar of blood in his ears he concentrated his hearing to the utmost pitch. Now he could hear the faint sounds of ore cars and perhaps miners and foremen, far down the tunnel that led from the far side of this chamber back to the pens. Even as faint as they were, they obscured further his chances of hearing whatever it was in the cavern with him.

The footsteps had stopped. Then came another metallic scrick scrick over the rail, heard against a light sniff. Oliver cowered, held his arms hard against his sides, knowing he smelled of sweat and fear. Far down the distant shaft a foreman spoke sharply. If he could reach that voice.... He resisted the urge to run for it, feeling sure somehow that whatever was in there with him was fast. over the rail, heard against a light sniff. Oliver cowered, held his arms hard against his sides, knowing he smelled of sweat and fear. Far down the distant shaft a foreman spoke sharply. If he could reach that voice.... He resisted the urge to run for it, feeling sure somehow that whatever was in there with him was fast.

Another scrick. scrick. Oliver cringed, trying to reduce his echo profile. There was a chip of rock under his hand. He fingered it, hand shaking. His forehead throbbed and he understood it was his third eye, straining to pierce the black silence and Oliver cringed, trying to reduce his echo profile. There was a chip of rock under his hand. He fingered it, hand shaking. His forehead throbbed and he understood it was his third eye, straining to pierce the black silence and see.... see....

A shape with pillar-thick legs, all in blocks of redblack. It was some sort of....

Scrick. Sniff. It was turning his way. A flick of the wrist, the chip of rock skittered, hitting ceiling and then floor, back in the direction he had come from. Sniff. It was turning his way. A flick of the wrist, the chip of rock skittered, hitting ceiling and then floor, back in the direction he had come from.

Very slow soft footsteps, as if the legs were somehow... they were coming in his direction.

He straightened and reached above him, hands scrabbling over the rough basalt. He felt a deep groove in the rock, and next to it a vertical hole. He jammed a hand in the hole, made a fist; put the fingers of the other hand along the side of the groove, and pulled himself up. The toes of his boot fit the groove, and he flattened up against the ceiling. In the lunar gravity he could stay there forever. Holding his breath.

Step... step... snuffle, fairly near the floor, which had given him the idea for this move. He couldn't turn to look. He felt something sc.r.a.pe the hip pocket of his pants and thought he was dead, but fear kept him frozen; and the sounds moved off into the distance of the vast chamber, without a pause.

He dropped to the ground and bolted doubled over for the far tunnel, which loomed before him redblack in the black, exuding air and faint noise. He plunged right in it, feeling one wall nick a knuckle. He took the sharp right he knew was there and threw himself down to the intersection of floor and wall. Footsteps padded by him, apparently running on the rails.

When he couldn't hold his breath any longer he breathed. Three or four minutes pa.s.sed and he couldn't bear to stay still. He hurried to the intersection, turned left and slunk to the bullpen. At the checkpoint the monitor's horn squawked and a foreman blasted him with a searchlight, pawed him roughly. "Hey!" The foreman held a big chunk of blue, taken from Oliver's hip pocket. What was this?

"Sorry boss," Oliver said jerkily, trying to see it properly, remembering the thing brushing him as it pa.s.sed under. "Must've fallen in." He ignored the foreman's curse and blow, and fell into the pen tearful with the pain of the light, with relief at being back among the others. Every muscle in him was shaking.

But Hester never came back from that shift.

Sometime later the foremen came back into their bullpen, wielding the lights and the prods to line them up against one mesh wall. Through pinp.r.i.c.k pupils Oliver saw just the grossest slabs of shapes, all grainy black-and-gray: Jakob was a big stout man, with a short black beard under the shaved head, and eyes that popped out, glittering even in Oliver's silhouette world.

"Miners are disappearing from your pen," the foreman said, in the miners' language. His voice was like the quartz they tunneled through occasionally: hard, and sparkly with cracks and stresses, as if it might break at any moment into a laugh or a scream.

No one answered.

Finally Jakob said, "We know."

The foreman stood before him. "They started disappearing when you arrived."

Jakob shrugged. "Not what I hear."

The foreman's searchlight was right on Jakob's face, which stood out brilliantly, as if two of the searchlights were pointed at each other. Oliver's third eye suddenly opened and gave the face substance: brown skin, heavy brows, scarred scalp. Not at all the white cutout blazing from the black shadows. "You'd better be careful, miner."

Loudly enough to be heard from neighboring pens, Jakob said, "Not my fault if something out there is eating us, boss."

The foreman struck him. Lights bounced and they all dropped to the floor for protection, presenting their backs to the boots. Rain of blows, pain of blows. Still, several pens had to have heard him.

Foremen gone. White blindness returned to black blindness, to the death velvet of their pure darkness. For a long time they lay in their own private worlds, hugging the warm rock of the floor, feeling the bruises blush. Then Jakob crawled around and squatted by each of them, placing his hands on their foreheads. "Oh yeah," he would say. "You're okay. Wake up now. Look around you." And in the after-black they stretched and stretched, quivering like dogs on a scent. The bulks in the black, the shapes they made as they moved and groaned... yes, it came to Oliver again, and he rubbed his face and looked around, eyes shut to help him see. "I ran into it on the way back in," he said.

They all went still. He told them what had happened. "The blue in your pocket?"

They considered his story in silence. No one understood it.

No one spoke of Hester. Oliver found he couldn't. She had been his friend. To live without that gaunt crow's voice....

Sometime later the side door slid up, and they hurried into the barn to eat. The chickens squawked as they took the eggs, the cows mooed as they milked them. The stove plates turned the slightest bit luminous-redblack, again-and by their light his three eyes saw all. Solly cracked and fried eggs. Oliver went to work on his vats of cheese, pulled out a round of it that was ready. Jakob sat at the rear of one cow and laughed as it turned to b.u.t.t his knee. Splish splish! Splish splish! Splish splish! Splish splish! When he was done he picked up the cow and put it down in front of its hay, where it chomped happily. Animal stink of them all, the many fine smells of food cutting through it. Jakob laughed at his cow, which b.u.t.ted his knee again as if objecting to the ridicule. "Little pig of a cow, little piglet. Mexican cows. They bred for this size, you know. On Earth the ordinary cow is as tall as Oliver, and about as big as this whole pen." When he was done he picked up the cow and put it down in front of its hay, where it chomped happily. Animal stink of them all, the many fine smells of food cutting through it. Jakob laughed at his cow, which b.u.t.ted his knee again as if objecting to the ridicule. "Little pig of a cow, little piglet. Mexican cows. They bred for this size, you know. On Earth the ordinary cow is as tall as Oliver, and about as big as this whole pen."

They laughed at the idea, not believing him. The buzzer cut them off, and the meal was over. Back into their pen, to lay their bodies down.

Still no talk of Hester, and Oliver found his skin crawling again as he recalled his encounter with whatever it was that sniffed through the mines. Jakob came over and asked him about it, sounding puzzled. Then he handed Oliver a rock. "Imagine this is a perfect sphere, like a baseball."

"Baseball?"

"Like a ball bearing, perfectly round and smooth you know."

Ah yes. Spherical geometry again. Trigonometry too. Oliver groaned, resisting the work. Then Jakob got him interested despite himself, in the intricacy of it all, the way it all fell together in a complex but comprehensible pattern. Sine and cosine, so clear! And the clearer it got the more he could see: the mesh of the bullpen, the network of shafts and tunnels and caverns piercing the jumbled fabric of the moon's body... all clear lines of redblack on black, like the metal of the stove plate as it just came visible, and all from Jakob's clear, patiently fingered, perfectly balanced equations. He could see through rock.

"Good work," Jakob said when Oliver got tired. They lay there among the others, shifting around to find hollows for their hips.

Silence of the off-shift. m.u.f.fled clanks downshaft, floor trembling at a detonation miles of rock away; ears popped as air smashed into the dead end of their tunnel, compressed to something nearly liquid for just an instant. Must have been a Boesman. Ringing silence again.

"So what is it, Jakob?" Solly asked when they could hear each other again.

"It's an element," Jakob said sleepily. "A strange kind of element, nothing else like it. Promethium. Number 61 on the periodic table. A rare earth, a lanthanide, an inner transition metal. We're finding it in veins of an ore called mon.a.z.ite, and in pure grains and nuggets scattered in the ore."

Impatient, almost pleading: "But what makes it so special?"

For a long time Jakob didn't answer. They could hear him thinking. Then he said, "Atoms have a nucleus, made of protons and neutrons bound together. Around this nucleus sh.e.l.ls of electrons spin, and each sh.e.l.l is either full or trying to get full, to balance with the number of protons-to balance the positive and negative charges. An atom is like a human heart, you see.

"Now promethium is radioactive, which means it's out of balance, and parts of it are breaking free. But promethium never reaches its balance, because it radiates in a manner that increases its instability rather than the reverse. Promethium atoms release energy in the form of positrons, flying free when neutrons are hit by electrons. But during that impact more neutrons appear in the nucleus. Seems they're coming from nowhere. So each atom of the blue is a power loop in itself, giving off energy perpetually. Some people say that they're little white holes, every single atom of them. Burning forever at nine hundred and forty curies per gram. Bringing energy into our universe from somewhere else. Little gateways."

Solly's sigh filled the black, expressing incomprehension for all of them. "So it's poisonous?"

"It's dangerous, sure, because the positrons breaking away from it fly right through flesh like ours. Mostly they never touch a thing in us, because that's how close to phantoms we are-mostly blood, which is almost light. That's why we can see each other so well. But sometimes a beta particle will hit something small on its way through. Could mean nothing or it could kill you on the spot. Eventually it'll get us all."

Oliver fell asleep dreaming of threads of light like concentrations of the foremen's fierce flashes, pa.s.sing right through him. Shifts pa.s.sed in their timeless round. They ached when they woke on the warm basalt floor, they ached when they finished the long work shifts. They were hungry and often injured. None of them could say how long they had been there. None of them could say how old they were. Sometimes they lived without light other than the robots' lasers and the stove plates. Sometimes the foremen visited with their scorching lighthouse beams every off-shift, shouting questions and beating them. Apparently cows were disappearing, cylinders of air and oxygen, supplies of all sorts. None of it mattered to Oliver but the spherical geometry. He knew where he was, he could see it. The three-dimensional map in his head grew more extensive every shift. But everything else was fading away....

"So it's the most powerful substance in the world," Solly said. "But why us? Why are we here?"

"You don't know?" Jakob said.

"They blanked us, remember? All that's gone."

But because of Jakob, they knew what was up there: the domed palaces on the lunar surface, the fantastic luxuries of Earth... when he spoke of it, in fact, a lot of Earth came back to them, and they babbled and chattered at the unexpected upwellings. Memories that deep couldn't be blanked without killing, Jakob said. And so they prevailed after all, in a way.

But there was much that had been burnt forever. And so Jakob sighed. "Yeah yeah, I remember. I just thought-well. We're here for different reasons. Some were criminals. Some complained."

"Like Hester!" They laughed.

"Yeah, I suppose that's what got her here. But a lot of us were just in the wrong place at the wrong time. Wrong politics or skin or whatever. Wrong look on your face."

"That was me, I bet," Solly said, and the others laughed at him. "Well I got a funny face, I know I do! I can feel it."

Jakob was silent for a long time. "What about you?" Oliver asked. More silence. The rumble of a distant detonation, like muted thunder.

"I wish I knew. But I'm like you in that. I don't remember the actual arrest. They must have hit me on the head. Given me a concussion. I must have said something against the mines, I guess. And the wrong people heard me."

"Bad luck."

"Yeah. Bad luck."

More shifts pa.s.sed. Oliver rigged a timepiece with two rocks, a length of detonation cord and a set of pulleys, and confirmed over time what he had come to suspect; the work shifts were getting longer. It was more and more difficult to get all the way through one, harder to stay awake for the meals and the geometry lessons during the off-shifts. The foremen came every off-shift now, blasting in with their searchlights and shouts and kicks, leaving in a swirl of afterimages and pain. Solly went out one shift cursing them under his breath, and never came back. Disappeared. The foremen beat them for it and Oliver shouted with rage. "It's not our fault! There's something out there, I saw it! It's killing us!"

Then next shift his little tendril of a vein bloomed, he couldn't find any rock around the blue: a big bole. He would have to tell the foremen, start working in a crew. He dismantled his clock.

On the way back he heard the footsteps again, shuffling along slowly behind him. This time he was at the entrance to the last tunnel, the pens close behind him. He turned to stare into the darkness with his third eye, willing himself to see the thing. Whoosh of air, a sniff, a footfall on the rail.... Far across the thin wedge of air a beam of light flashed, making a long narrow cone of white talc. Steel tracks gleamed where the wheels of the car burnished them. Pupils shrinking like a snail's antennae, he stared back at the footsteps, saw nothing. Then, just barely, two points of red: retinas, reflecting the distant lance of light. They blinked. He bolted and ran again, reached the foremen at the checkpoint in seconds. They blinded him as he panted, pa.s.sed him through and into the bullpen.

After the meal on that shift Oliver lay trembling on the floor of the bullpen and told Jakob about it. "I'm scared, Jakob. Solly, Hester, Freeman, mute Lije, Naomi-they're all gone. Everyone I know here is gone but us."

"Free at last," Jakob said shortly. "Here, let's do your problems for tonight."

"I don't care about them."

"You have to care about them. Nothing matters unless you do. That blue is the mind of the moon being torn away, and the moon knows it. If we learn what the network says in its shapes, then the moon knows that too, and we're suffered to live."

"Not if that thing finds us!"

"You don't know. Anyway nothing to be done about it. Come on, let's do the lesson. We need it."

So they worked on equations in the dark. Both were distracted and the work went slowly; they fell asleep in the middle of it, right there on their faces.

Shifts pa.s.sed. Oliver pulled a muscle in his back, and excavating the bole he had found was an agony of discomfort. When the bole was cleared it left a s.p.a.ce like the interior of an egg, ivory and black and quite smooth, punctuated only by the bluish spots of other tendrils of mon.a.z.ite extending away through the basalt. They left a catwalk across the central s.p.a.ce, with decks cut into the rock on each side, and ramps leading to each of the veins of blue; and began drilling on their own again, one man and robot team to each vein. At each shift's end Oliver rushed to get to the egg-chamber at the same time as all the others, so that he could return the rest of the way to the bullpen in a crowd. This worked well until one shift came to an end with the hoist chock-full of the ore. It took him some time to dump it into the ore car and shut down.

So he had to cross the catwalk alone, and he would be alone all the way back to the pens. Surely it was past time to move the pens closer to the shaft heads! He didn't want to do this....

Halfway across the catwalk he heard a faint noise ahead of him. Scrick; scriiiiiiik. Scrick; scriiiiiiik. He jerked to a stop, held the rail hard. Couldn't reach the ceiling here. Back stabbing its protest, he started to climb over the railing. He could hang from the underside. He jerked to a stop, held the rail hard. Couldn't reach the ceiling here. Back stabbing its protest, he started to climb over the railing. He could hang from the underside.

He was right on the top of the railing when he was seized up by a number of strong cold hands. He opened his mouth to scream and his mouth was filled with wet clay. The blue. His head was held steady and his ears filled with the same stuff, so that the sounds of his own terrified sharp nasal exhalations were suddenly cut off. Promethium; it would kill him. It hurt his back to struggle on. He was being carried horizontally, ankles whipped, arms tied against his body. Then plugs of the clay were shoved up his nose and in the middle of a final paroxysm of resistance his mind fell away into the black.

The lowest whisper in the world said, "Oliver Pen Twelve." He heard the voice with his stomach. He was astonished to be alive.

"You will never be given anything again. Do you accept the charge?"

He struggled to nod. I never wanted anything! he tried to say. I only wanted a life like anyone else.

"You will have to fight for every sc.r.a.p of food, every swallow of water, every breath of air. Do you accept the charge?"

I accept the charge. I welcome it.

"In the eternal night you will steal from the foremen, kill the foremen, oppose their work in every way. Do you accept the charge?" I welcome it.

"You will live free in the mind of the moon. Will you take up this charge?"

He sat up. His mouth was clear, filled only with the sharp electric aftertaste of the blue. He saw the shapes around him: there were five of them, five people there. And suddenly he understood. Joy ballooned in him and he said, "I will. Oh, I will!"

A light appeared. Accustomed as he was either to no light or to intense blasts of it, Oliver at first didn't comprehend. He thought his third eye was rapidly gaining power. As perhaps it was. But there was also a laser drill from one of the A robots, shot at low power through a cylindrical ceramic electronic element, in a way that made the cylinder glow yellow. Blind like a fish, open-mouthed, weak eyes gaping and watering floods, he saw around him Solly, Hester, Freeman, mute Elijah, Naomi. "Yes," he said, and tried to embrace them all at once. "Oh, yes."

They were in one of the long-abandoned caverns, a flat-bottomed bole with only three tendrils extending away from it. The chamber was filled with objects Oliver was more used to identifying by feel or sound or smell: pens of cows and hens, a stack of air cylinders and suits, three ore cars, two B robots, an A robot, a pile of tracks and miscellaneous gear. He walked through it all slowly, Hester at his side. She was gaunt as ever, her skin as dark as the shadows; it sucked up the weak light from the ceramic tube and gave it back only in little points and lines. "Why didn't you tell me?"

"It was the same for all of us. This is the way."

"And Naomi?"

"The same for her too; but when she agreed to it, she found herself alone."

Then it was Jakob, he thought suddenly. "Where's Jakob?"

Rasped: "He's coming, we think."

Oliver nodded, thought about it. "Was it you, then, following me those times? Why didn't you speak?"

"That wasn't us," Hester said when he explained what had happened. She cawed a laugh. "That was something else, still out there...."

Then Jakob stood before them, making them both jump. They shouted and the others all came running, pressed into a ma.s.s together. Jakob laughed. "All here now," he said. "Turn that light off. We don't need it."

And they didn't. Laser shut down, ceramic cooled, they could still see: they could see right into each other, red shapes in the black, radiating joy. Everything in the little chamber was quite distinct, quite visible. visible.

"We are the mind of the moon."

Without shifts to mark the pa.s.sage of time Oliver found he could not judge it at all. They worked hard, and they were constantly on the move: always up, through level after level of the mine. "Like sh.e.l.ls of the atom, and we're that particle, busted loose and on its way out." They ate when they were famished, slept when they had to. Most of the time they worked, either bringing down shafts behind them, or dismantling depots and stealing everything Jakob designated theirs. A few times they ambushed gangs of foremen, killing them with laser cutters and stripping them of valuables; but on Jakob's orders they avoided contact with foremen when they could. He wanted only material. After a long time-twenty sleeps at least-they had six ore cars of it, all trailing an A robot up long-abandoned and empty shafts, where they had to lay the track ahead of them and pull it out behind, as fast as they could move. Among other items Jakob had an insatiable hunger for explosives; he couldn't get enough of them.

It got harder to avoid the foremen, who were now heavily armed, and on their guard. Perhaps even searching for them, it was hard to tell. But they searched with their lighthouse beams on full power, to stay out of ambush: it was easy to see them at a distance, draw them off, lose them in dead ends, detonate mines under them. All the while the little band moved up, rising by infinitely long detours toward the front side of the moon. The rock around them cooled. The air circulated more strongly, until it was a constant wind. Through the seismometers they could hear from far below the rumbling of cars, heavy machinery, detonations. "Oh they're after us all right," Jakob said. "They're running scared."

He was happy with the booty they had acc.u.mulated, which included a great number of cylinders of compressed air and pure oxygen. Also vacuum suits for all of them, and a lot more explosives, including ten Boesmans, which were much too big for any ordinary mining. "We're getting close," Jakob said as they ate and drank, then tended the cows and hens. As they lay down to sleep by the cars he would talk to them about their work. Each of them had various jobs: mute Elijah was in charge of their supplies, Solly of the robot, Hester of the seismography. Naomi and Freeman were learning demolition, and were in some undefined sense Jakob's lieutenants. Oliver kept working at his navigation. They had found charts of the tunnel systems in their area, and Oliver was memorizing them, so that he would know at each moment exactly where they were. He found he could do it remarkably well; each time they ventured on he knew where the forks would come, where they would lead. Always upward.

But the pursuit was getting hotter. It seemed there were foremen everywhere, patrolling the shafts in search of them. "Soon they'll mine some pa.s.sages and try to drive us into them," Jakob said. "It's about time we left."

"Left?" Oliver repeated.

"Left the system. Struck out on our own."

"Dig our own tunnel," Naomi said happily.

"Yes."