Blocky pixels flickered across his vision, within his closed eyes. Startled, he looked up.

Sarfi was kneeling before him; she had brushed her Virtual fingertips through his skull, his eyes. He hadn't even known she had come here.

"I know it's hard to accept," she said. "My mother spent a long time making me understand. You just have to open your mind."

"I am no fool," he said sharply. "I can imagine a map of all the logical possibilities of a universe. But it would be just that-a map, a theoretical construct, a thing of data and logic. It would not be a place. The universe doesn't feel like that. I feel time pa.s.sing. I don't experience disconnected instants, Reth's dusty reality."

"Of course not," said Reth. "But you must understand that everything we know of the past is a record embedded in the present-the fossils and geology of Earth, so cruelly obliterated by the ax, even the traces of chemicals and electricity in your own brain that comprise your memory, maintaining your illusion of past times ... Gemo, may I-"

Gemo nodded, unsmiling.

Reth tapped a data slate. Sarfi froze, becoming a static, inanimate sculpture of light. Then, after perhaps ten seconds, she melted, began to move once more.

She saw Hama staring at her. "What's wrong?"

Reth, ignoring her, said, "The child contains a record of her own shallow past, embedded in her programs and data stores. She is unaware of the intervals of time when she is frozen, or deactivated. If I could start and stop you, Hama Druz, you would wake protesting that your memories contained no gaps.

But your memories themselves would have been frozen. I could even chop up your life and rearrange its instants in any way I chose; at each instant you would have an intact set of memories, a record of a past, and you would believe yourself to have lived through a continuous consistent reality.

"And thus the maximal-reality dust grains contain embedded within themselves a record of the eras which "preceded" them. Each grain contains brains, like yours and mine, with "memories" embedded in them, frozen like sculptures. And history emerges in configuration s.p.a.ce because those rich grains are then drawn, by a least-energy matching principle, to the grains which "precede" and "follow" them...

You see?"

Sarfi looked to Gemo. "Mother? What does he mean?..."

Gemo watched her clinically. "Sarfi has been reset many times, of course," she said absently. "I had no wish to see her grow old, accreted with worthless memory. It was rather like an Extirpation, you see.

The ax sought to reset humanity, to abolish the memory of the race. In the ultimate realization, we would have become a race of children, waking every day to a fresh world, every day a new creation. It was cruel, of course. But, theoretically, intriguing. Don't you think?"

Sarfi was trembling.

Now Reth began telling Gemo, rapidly and with enthusiasm, of his plans to explore his continent of configurations. "No human mind could apprehend that multidimensional domain unaided, of course. But it can be modeled, with metaphors-rivers, seas, mountains. It is possible to explore it . . ."

Hama said, "But, if your meta-universe is static, timeless, how could it be experienced? For experience depends on duration."

Reth shook his head impatiently. He tapped his data slate and beckoned to Sarfi. "Here, child."

Hesitantly, she stepped forward.

She trailed a worm-like tube of light, as if her image had been captured at each moment in some invisible emulsion.

She emerged, blinking, at the other end of the tube, and looked back at it, bewildered.

"Stop these games," Hama said tightly.

"You see?" Reth said. "Here is an evolution of Sarfi's structure, but mapped in s.p.a.ce, not time. But it makes no difference to Sarfi. Her memory at each frozen instant contains a record of her walking across the floor toward me- doesn't it, dear? And thus, in static configuration s.p.a.ce, sentient creatures could have experiences, afforded them by the evolution of information structures across s.p.a.ce."

Hama turned to Sarfi. "Are you all right?"

"What do you think?"

"I think Reth may be insane," he said.

She stiffened, pulling back. "Don't ask me. I'm not even a mayfly, remember?"

"It is a comforting philosophy, Kama," Gemo said. "Nothing matters, you see: not even death, not even the Extirpation. For we persist, each moment exists forever, in a great universe ..."

It was a philosophy of decadence, Hama thought angrily. A philosophy of morbid contemplation, a consolation for ageless pharaohs as they sought to justify the way they administered the suffering of their fellow creatures. No wonder it appealed to them so much.

Gemo and Reth talked on, more and more rapidly, entering realms of speculation he couldn't begin to follow.

Callisto told Asgard what she was intending to do.

She walked along the narrowing beach, seeking sc.r.a.ps of people, of newborns and others, washed up by the pitiless black sea.

She picked up what looked like a human foot. It was oddly dry, cold, the flesh and even the bones crumbling at her touch.

She collected as many of these hideous shards as she could hold, and toiled back along the barren dust.

Then she worked her way through the forest back to the great tree, where she had encountered the creature called Night. She paused every few paces and pushed a section of corpse into the ground. She covered each fragment over with ripped-up gra.s.s and bits of bark.

'You're crazy," Asgard said, trailing her, arms full of dried, crumbling flesh and bone.

'I know," Callisto said. "I'm going anyway."

Asgard would not come far enough to reach the tree itself. So Callisto completed her journey alone.

Once more she reached the base of the tree. Once more, her heart thumping hard, she began to climb.

The creature, Night, seemed to have expected her. He moved from branch to branch, far above, a ma.s.sive blur, and he clambered with ferocious purpose down the trunk.

She scrambled hurriedly back to the ground.

He followed her-but not all the way to the ground. He clung to his trunk, his broad face broken by that immense, b.l.o.o.d.y mouth, hissing at her.

She glowered back, and took a tentative step toward the tree. "Come get me," she muttered. "What are you waiting for?" She took a piece of corpse (a hand-briefly her stomach turned), and she hurled it up at him.

He ducked aside, startled. But he swiveled that immense head. As the hand descended he caught it neatly hi his scoop of a mouth, crunched once and swallowed it whole. He looked down at her with new

interest.

And he took one tentative step toward the ground.

"That's it," she crooned. "Come on. Come eat the flesh. Come eat me, if that's what you want-"

Without warning he leapt from the trunk, immense hands splayed.

She screamed and staggered back. He crashed to the ground perhaps an arm's length from her. One ma.s.sive fist slammed into her ankle, sending a stab of pain that made her cry out.

If he'd landed on top of her he would surely have crushed her.

The beast, winded, was already clambering to his feet.

She got to her feet and ran, ignoring the pain of her ankle.

Night followed her, his lumbering four-legged pursuit slow but relentless. As she ran she kicked open her buried caches of body parts. He snapped them up and gobbled them down, barely slowing. The morsels seemed pathetically inadequate in the face of Night's giant reality.

She burst out onto the open beach, still running for her life. She reached the lip of the sea, skidding to a halt before the lapping black liquid. Her plan had been to reach the sea, to lure Night into it.

But when she turned, she saw that Night had hesitated on the fringe of the forest, blinking in the light.

Perhaps he was aware that she had deliberately drawn him here.

He stepped forward deliberately, his immense feet sinking into the soft dust. There was no need for him to rush.

Callisto was already exhausted, and, trapped before the sea, there was nowhere for her to run.

Now that he was out in the open she saw how far from the human form he had become, with his body a distorted slab of muscle, a mouth that had widened until it stretched around his head. And yet sc.r.a.ps of clothing clung to him, the remnants of a coverall of the same unidentifiable color as her own. Once this creature, too, had been a newborn here, landing screaming on this desolate beach.

He towered over her, and she wondered how many unfortunates he had devoured to reach such proportions.

Beyond his looming shoulder, she could see Asgard, pacing back and forth along the beach.

"Great plan," Asgard called. "Now what?" "I-"

Night raised up on his hind legs, huge hands pawing at the air over her head. He roared wordlessly, and b.l.o.o.d.y breath gushed over her.

Close your eyes, Callisto thought. This won't hurt.

"No," Asgard said. She took a step toward the looming beast, began to run.

"No, no, no!" With a final yell she hurled herself at his back.

He looked around, startled, and swiped at Asgard with one giant paw. She was flung away like a sc.r.a.p of bark, to land in a heap on the dust. But Night, off-balance, was stumbling backward, back toward the sea.

When his foot sank into the oily ocean, he looked down, as if surprised.

Even as he lifted his leg from the fluid the flesh was drying, crumbling, the muscles and bone sloughing away in layers of purple and white. He roared his defiance, and cuffed at the sea-then gazed in horror at one immense hand left shredded by contact with the entropic ooze.

He began to fall, slowly, ponderously. Without a splash, the fluid opened up to accept his immense bulk.

He was immediately submerged, the shallow fluid flowing eagerly over him.

In one last burst of defiance he broke the surface, mouth open, his flesh dissolving. His face was restored, briefly, to the human, his eyes a startling blue. He cried out, his voice thin: "Reth!"

The name sent a shiver of recognition through Callisto.

Then he fell back, and was gone.

She hurried to Asgard.

Asgard's chest was crushed, she saw immediately, imploded to an implausible degree, and her limbs were splayed around her at impossible angles. Her face was growing smooth, featureless, like a child's, beautiful in its innocence. Her gaze slid over Callisto.

Callisto cradled Asgard's head. "This won't hurt," she murmured. "Close your eyes." Asgard sighed, and was still.

"Let me tell you about pharaohs," Nomi said bitterly.

Kama listened in silence.

They stood on the Valhalla ridge, overlooking the old, dark settlement; the brightest point on the silver- black surface of Callisto was their own lifedome.

Nomi said, "This was just after the ax left. I got this from a couple of our people who survived, who were there. There was a nest of the pharaohs, in one of the biggest Conurbations-one of the first to be constructed, one of the oldest. The pharaohs retreated into a pit, under the surface dwellings.

They fought hard; we didn't know why. They had to be torched out. A lot of good people, good mayflies, died that day. When our people had dealt with the pharaohs, shut down the mines and drone robots and b.o.o.by-traps ... after all that, they went into the pit. It was dark. But it was warm, the air was moist, and there was movement everywhere. Small movements. And, so they say, there was a smell. Of milk-"

Nomi was silent for a long moment; Hama waited.

"Hama, I can't have children. I grew up knowing that. So maybe I ought to find some pity for the pharaohs. They don't breed true-like Gemo and Sarfi. But Sarfi is the exception, I think. Sometimes their children are born with ax immortality. But-"

"Yes?"

"But they don't grow. They stop developing, at the age of two years or one year or six months or a month; some of them even stop growing before they are ready to be born, and have to be plucked from their mothers' wombs.

"And that was what our soldiers found in the pit, Hama. Racked up like specimens in a lab, hundreds of them. Must have been acc.u.mulating for centuries.

Plugged into machines, mewling and crying."

"Lethe." Maybe Gemo is right, Hama thought; maybe the pharaohs really have paid a price we can't begin to understand.

"The pit was torched..."

Hama thought he saw a shadow pa.s.s across the sky, the scattered stars. "Why are you telling me this, Nomi?"

Nomi pointed. "There's a line of shallow graves over there. Not hard to find, in the end."

"Ah."

"The killings seemed to be uniform, the same method every time. A laser to the head. The bodies seemed peaceful," Nomi mused. "Almost as if they welcomed it."

He had killed them. Reth had killed the other pharaohs who came here, one by one. But why?

And why would an immortal welcome death? Only if- his mind raced-only if she were promised a better place to goEverything happened at once.