He hadn't been able to accept that she was dead then. Even having seen her lifeless form sprawled on the cold tiles of the bathroom floor, he still hadn't accepted it.

But now- There she was. Dead. Pa.s.sive storage. Backed-up; part of the archive of humanity.

He realized now that he couldn't talk to her. There was no way to interact with Mary, no way to tell her that what she thought had happened hadn't really.

Oh, yes, he could access her memories, leaf through her past.

But he couldn't communicate with her.

When he'd crouched down by her tombstone, he'd felt as though maybe, somehow, he was connecting with her, somehow she could hear his words. He'd wanted to apologize-not for anything he'd done, but for the fact that he hadn't protected her from the predation of that therapist, that her daddy hadn't been there for her when she'd needed him the most.

But even if he'd spoken the words aloud by the tombstone, she couldn't have heard him. The other hexagons stared at him like eyes, but this one was so abysmally dark there could be no doubt.

She was totally, completely, irretrievably gone.

There was no way to make amends.

And yet- And yet he found himself not feeling destroyed by that fact.

On the contrary, he felt a release, a letting go.

For so long, in the dark corners of his mind, despite his intellectual atheism, he'd thought that somewhere she was still conscious, still aware, still suffering.

Still hating him.

But she wasn't. In every sense of the word, Mary simply wasn't. She no longer existed.

But still, it wasn't over.

Not yet, not quite.

Kyle had cried when his daughter died.

He'd cried with anger, furious that she could do that.

He'd cried with outrage, unable to understand.

But he hadn't cried for for her. her.

And suddenly his eyes were br.i.m.m.i.n.g over, tears welling up and spilling out.

He did cry for her now-only for her. For the sadness of a beautiful life cut short, for all the things that she had been, and for all the other things she might have become, but never did.

He cried so much that his eyes kept closing, the interior of the construct reappearing in his mind.

But he wasn't through yet.

He understood, finally, why Heather had brought him here, and what he had to do.

He wiped his eyes and then opened them up all the way. Psychos.p.a.ce reformed around him, with the black hexagon that had been Mary still facing him.

He took a deep breath and let it out, feeling so much pent-up emotion escape with it.

And then he said one gentle, heartfelt word.

"Good-bye."

He let it echo in his mind softly for a few moments. Then he closed his eyes again, reached forward and pressed the stop b.u.t.ton, prepared at last to return to the world of the living.

35.

Kyle disengaged the cubic door. Heather had clearly been standing close by; he felt her hands lifting the door from the other side.

He swung his feet over the ledge and climbed out. Heather looked at him; doubtless she could tell he had been crying.

Kyle managed a small smile. "Thank you," he said. His daughter wasn't in the room. "Where's Becky?"

"She had to go. She's got a date with Zack tonight." Kyle nodded, pleased. But he could see concern on Heather's face-and he suddenly realized what the concern was. She knew him, of course, and, of late, really really knew him. She had to realize that before looking at Mary's dark hexagon, he would have snuck a peek at his wife's mind, too. The expression on Heather's face-he'd seen it once before, ages ago, the first time they'd made out in a well-lit room instead of groping in the darkness. The first time he'd seen her naked. She'd looked precisely this way then: embarra.s.sed, scared that she didn't measure up to his imaginings, and yet ever so provocative. knew him. She had to realize that before looking at Mary's dark hexagon, he would have snuck a peek at his wife's mind, too. The expression on Heather's face-he'd seen it once before, ages ago, the first time they'd made out in a well-lit room instead of groping in the darkness. The first time he'd seen her naked. She'd looked precisely this way then: embarra.s.sed, scared that she didn't measure up to his imaginings, and yet ever so provocative.

He spread his arms, swept her up in them, and hugged her so tight it hurt.

After a minute, they pulled apart. Kyle took her hand, running his index finger around her wedding ring. "I love you," he said. He sought her eyes. "I love you, and I want to spend the rest of my life getting to know you."

Heather smiled at him-and at the memory. "I love you, too," she said, for the first time in a year. He brought his face down to hers, and they kissed. When their lips separated, she said it again, "I do do love you." love you."

Kyle nodded. "I know. I really really know." know."

But Heather's expression waxed grim. "Mary?"

He was quiet for a moment, then: "I've made my peace."

Heather nodded.

"It's incredible," said Kyle. "The overmind. Absolutely incredible." He paused. "And yet . . ."

"What?"

"Well, remember Professor Papineau? How mind-expanding I always said his cla.s.ses were? He taught me a lot of quantum physics-but I never got it, not really, not down deep. Things kept niggling. But it makes sense now."

"How?"

He spread his arms, as if thinking of a way to express it all, "Do you know about Schrodinger's cat?"

"I've heard the term," said Heather.

"Simple thought experiment: you seal a cat in a box along with a vial of poison gas and a trigger that'll release the gas if a quantum event that has precisely a fifty-fifty chance of happening in the next hour occurs. Without opening the box an hour later, can you say whether the cat is alive or dead?"

Heather frowned. "No."

" 'No' is right. But not because you can't tell which it is. Rather, because it's neither. neither. The cat is neither alive nor dead, but instead is a superposition of wave fronts-a mingled combination of both possibilities. Only the act of opening the box and looking causes the wave front to resolve itself into one concrete reality. That's quantum mechanics: things are indeterminate until they're observed." The cat is neither alive nor dead, but instead is a superposition of wave fronts-a mingled combination of both possibilities. Only the act of opening the box and looking causes the wave front to resolve itself into one concrete reality. That's quantum mechanics: things are indeterminate until they're observed."

"All right."

"But say I look in the box first, see that the cat's still alive, then seal the box up. You come along a few minutes later and you open the box and look, unaware that I've previously had a peek. What do you see?"

"A living cat."

"Precisely! My having observed it shapes reality for you, too. That's long been one of the problems in quantum mechanics: why do the observations of a single observer create a concrete reality for everyone simultaneously? The answer, of course, is that everyone is part of the overmind, so the observation made by one person is the observation made by all people-indeed, quantum mechanics requires requires the overmind in order to work." the overmind in order to work."

Heather made an impressed face. "Interesting." She paused. "So what do we do now?"

"We tell the world," said Kyle.

"Do we?" asked Heather.

"Sure. Everyone has a right to know."

"But it'll change everything," said Heather. "Everything. "Everything. The civilization we know will cease to exist." The civilization we know will cease to exist."

"If we don't tell, somebody else will."

"Maybe. Maybe no one else will figure it out."

"It's inevitable. h.e.l.l, now that you've done it, it's part of the collective unconscious-someone will have it come to them in a dream."

"But people will take advantage of this-the ability to spy, to steal thoughts. Whole societies will collapse."

Kyle frowned. "I can't believe that the Centaurs would send us instructions on how to build something that would lead to our downfall. Why bother? We can't possibly be a threat to them."

"I suppose," said Heather.

"So let's go public."

Heather frowned. "Today is Sat.u.r.day; I doubt that many science journalists are working on the weekend in the summer, so we can't even begin to call a press conference until Monday. And if we want a good turnout, we'll have to give the journalists a day or two's notice."

Kyle nodded acceptance. "But what if someone else does announce the discovery over the weekend?"

Heather considered. "Well, if that happens, I can always point to the overmind archive and say, 'Look, there's the proof that I'd figured it out before you.' " She paused. "But I suppose that's old-style thinking," she said with a little shrug. "In the new world we're about to create, I doubt the idea of primacy will have any meaning."

Heather spent all day Sunday exploring psychos.p.a.ce; Kyle and Becky were taking turns doing the same thing over in Mullin Hall, where you really did need someone to help remove the cubic door.

For Heather, it was like swimming in a pristine mountain lake, remote and pellucid, knowing that no one else had ever stumbled across it, knowing that she was the first to ever behold its beauty, to immerse herself in it, to feel it wash over her.

But like landscapes everywhere, the life on the surface was built on top of death, new shoots thrusting through a blanket of decaying organic matter. Although there were many living people whose minds Heather wanted to enter, there were also countless dead ones she wished to connect with-and somehow, entering the dead seemed less an invasion, less a violation of privacy.

Kyle hadn't spent much time in the dark archive of Mary's mind, and Heather had yet to touch one of the black hexagons. But now it was time.

Actually, in this case, she didn't have to search for the hexagon. All she had to do was enter herself-an easy Necker transformation from the hexagon she'd identified as Kyle-and then, from her own memories, conjure up a concrete image of her desired target, and Necker into him.

Josh Huneker.

Dead now for twenty-three years.

She hadn't been haunted by him, of course. For most of that time, she hadn't thought about him at all, even though in at least one significant way, he'd had a huge impact on her life; it was he who had introduced her to the fascinations of SETI, after all, and so, quite literally, if it hadn't been for her relationship with Josh, she wouldn't be here now.

But she was was here. And if there had been an earlier alien message, one that she'd never seen, one that no one still alive had ever seen, then she had to know. here. And if there had been an earlier alien message, one that she'd never seen, one that no one still alive had ever seen, then she had to know.

One didn't need a quantum computer anymore to crack Huneker's secret-or anyone else's secret, for that matter. Privacy-even the privacy of the grave-no longer existed.

She swapped into Huneker's mind.

It was unlike any mind she'd been in before. This one was stone-cold dead, with no active images, no active thoughts. Heather felt as though she were adrift in a starless, moonless night, on a silent sea made of the blackest ink.

But the archive was here. What Josh had been-and whatever had tortured him-was stored here.

She imagined herself as she was back then. Younger, thinner, and if not actually pretty, possessed of an eagerness that might have pa.s.sed for such.

And after a moment, it clicked.

She saw herself as he had seen her all those years ago: smooth-skinned; short, punky hair, then dyed blond; three little rings of silver-another Toronto experience!-piercing the curve of her left ear.

He had not loved her.

She wasn't really surprised. He'd been the good-looking grad student, and she'd practically thrown herself at him. Oh, he'd had feelings for her-and they were were s.e.xual. And yet he'd already committed, he thought, to a different lifestyle. s.e.xual. And yet he'd already committed, he thought, to a different lifestyle.

He was confused, torn apart.

He'd planned to kill himself. Of course it had been planned-he'd had to think to bring the a.r.s.enic.

And like his idol Alan Turing, he had bitten into a poisoned apple. He'd sampled forbidden knowledge.

She'd never known how tortured he'd been, how much he'd agonized over what to do about her, and about himself.

She couldn't say good-bye; there was no one to say good-bye to. Whatever had happened all those years ago was immutable-and over.

But she was not ready to pull out of his mind.

She'd never been to the Algonquin Radio Observatory, closed now for almost a quarter of a century. It took numerous tries to connect with his memories of the place-moving obliquely from his memories of her to his painful introspection up there, snow barricading the door. But at last she managed it.

Incredibly, there had had been an alien message. been an alien message.

It formed a Drake pictogram; if Chomsky's theories had any validity across species boundaries, the one syntactic structure that might be shared by all races communicating by radio was the grid made up of a prime number of columns by a prime number of rows.