"And yet you turned away from it all. You ran and hid, out here. Look, I know how much it must have hurt, when Miriam Berg decided to fly out with the Cauchy rather than stay with you. But—"

"I’m not hiding, damn you," Michael said, striving to mask a flare of anger. "I’ve told you what I’m doing out here. The quark nuggets could provide new insight into the fundamental structure of matter—"

"You’re a dilettante," Harry said, and he sat back in his chair dismissively. "That’s all. You have no control over what comes wafting in to you from the depths of time and space. Sure, it’s intriguing. But it isn’t science. It’s collecting butterflies. The big projects in the inner System, like the Serenitatis accelerator, left you behind years ago." Harry’s eyes were wide and unblinking. "Tell me I’m wrong."

Michael, goaded, threw his whiskey globe to the floor. It smashed against the clear surface, and the yellow fluid, pierced by comet light, gathered stickily around rebounding bits of glass. "What the hell do you want?"

"You let yourself grow old, Michael," Harry said sadly. "Didn’t you? And — worse than that — you let yourself stay old."

"I stayed human," Michael growled. "I wasn’t going to have my head dumped out into a chip."

Harry got out of his chair and approached his son. "It isn’t like that," he said softly. "It’s more like editing your memories. Classifying, sorting. Rationalizing."

Michael snorted. "What a disgusting word that is."

"Nothing’s lost, you know. It’s all stored — and not just on chips, but in neural nets you can interrogate — or use to feed Virtuals, if you like." Harry smiled. "You can talk to your younger self. Sounds like your ideal occupation, actually."

"Look." Michael closed his eyes and pressed his fingers against the bridge of his nose. "I’ve thought through all of this. I’ve even discussed it with you before. Or have you forgotten that too?"

"There isn’t really a choice, you know."

"Of course there is."

"Not if you want to stay human, as you say you do. Part of being human is to be able to think fresh thoughts — to react to new people, new events, new situations. Michael, the fact is that human memory has a finite capacity. The more you cram in there the longer the retrieval times become. With AS technology—"

"You can’t make yourself a virgin by transplanting a hymen, for God’s sake."

"You’re right." Harry reached out a hand to his son — then hesitated and dropped it again. "Coarse, as usual, but correct. And I’m not telling you that tidying up your memories is going to restore your innocence. Your thrill at first hearing Beethoven. The wonder of your first kiss. And I know you’re frightened of losing what you have left of Miriam."

"You presume a hell of a lot, damn you."

"But, Michael — there isn’t an option. Without it, there’s only fossilization." Harry smiled ruefully. "I’m sorry, son. I didn’t mean to tell you how to run your life."

"No. You never did, did you? It was always just a kind of habit." Michael crossed to a serving hatch and, with rapid taps at a keypad icon, called up another whiskey. "Tell me what was so urgent that you had to beam out a Virtual package."

Harry paced slowly across the clear floor; his silent footsteps, weight-laden in the absence of gravity and suspended over the ocean of space, gave the scene an eerie aspect. "The Interface," he said.

Michael frowned. "The project? What about it?"

Harry considered his son with genuine sympathy. "I guess you really have lost track of your life, out here. Michael, it’s a century now since the launch of the Cauchy. Don’t you recall the mission plan?"

Michael thought it over. A century -

"My God," Michael said. "It’s time, isn’t it?"

The Cauchy should have returned to Sol, in that remote future. Michael cast an involuntary glance up at the cabin wall, in the direction of Jupiter. The second wormhole portal still orbited Jupiter patiently; was it possible that — even now — a bridge lay open across a millennium and a half?

"They sent me to fetch you," Harry was saying ruefully. "I told them it was a waste of time, that we’d argued since you were old enough to talk. But they sent me anyway. Maybe I’d have a better chance of persuading you than anybody else."

Michael felt confused. "Persuading me to do what?"

"To come home." The Virtual glanced around the cabin. "This old tub can still fly, can’t she?"

"Of course she can."

"Then the quickest way for you to return is to come in voluntarily in this thing. It will take you about a year. It would take twice as long to send a ship out to fetch you—"

"Harry. Slow down, damn it. Who are ‘they’? And why am I so important, all of a sudden?"

" ‘They’ are the Jovian government. And they have the backing of all the intergovernmental agencies. System-wide, as far as I know. And you’re important because of the message."

"What message?"

Harry studied his son, his too young face steady, his voice level. "Michael, the portal has returned. And something’s emerged from the wormhole. A ship from the future. We’ve had one message from it, on microwave wavelengths; we suspect the message was smuggled out, against the will of whoever’s operating the ship."

Michael shook his head. Maybe he had let himself get too old; Harry’s words seemed unreal — like descriptions of a dream, impossible to comprehend. "Could the message be translated?"

"Fairly easily," said Harry dryly. "It was in English. Voice, no visual."

"And? Come on, Harry."

"It asked for you. By name. It was from Miriam Berg."

Michael felt the breath seep out of him, against his will.

His father’s Virtual crouched before him, one hand extended, close enough to Michael’s face for him to make out individual pixels. "Michael? Are you all right?"

Again Jasoft Parz was suspended in space before a Spline ship.

The freighter was a landscape of gray flesh. Parz peered into an eyeball that, swiveling, gazed out at him from folds of hardened epidermis, and Parz felt a strange sense of kinship with the Spline, this fellow client creature of the Qax.

Parz was aware of a hundred weapons trained upon his fragile flitter — perhaps including, even, the fabled gravity-wave starbreaker beams, purloined by the Qax from the Xeelee.

He wanted to laugh. A wall of nonexistence was, perhaps, hurtling toward them from out of the altered past, and yet still they brandished their toy weapons against an old man.

"Ambassador Jasoft Parz." The Governor’s translated voice was, as ever, soft, feminine, and delicious, and quite impossible to read.

Parz kept his voice steady. "I am here, Governor."

There was a long silence. Then the Governor said, "I must ask your help."

Parz felt a kind of tension sag out of him, and it was as if the muscles of his stomach were folding over each other. How he had dreaded this call to meet with the Governor — his first journey into orbit since that fateful moment a week earlier when he had been forced to witness the humiliation of the Qax at the hands of the rebellious rabble who had escaped through the Interface portal. Parz had returned to his normal duties — though that had been difficult enough; even the rarefied diplomatic circles that controlled the planet were alive with talk of that single, staggering act of defiance. At times Parz had longed to walk away from the heavy cordon of security that surrounded his life and immerse himself in the world of the common man. He would be destroyed as soon as they discovered he was a collaborator, of course… but maybe it would be worth it, to hear the delicious note of hope on a thousand lips.

But he had not the courage, or the foolhardiness, to do any such thing. Instead, he had waited for the Governor to decide what to do. It would be quite within the imagination of the Qax to find a way to punish the planet as a whole for the actions of a few individuals.