Or maybe it would turn out to be over the edge. In that case, he'd spend even more lunch hours in his cubicle in the days ahead than he had for the past six months. He was caught up on everything the people above him wanted. They thought he worked his long hours to stay that way.

"What they don't know won't hurt them,"

Justin murmured. "And it may do me some good."

He didn't think anyone else had combined superstring physics, chaos theory, and virtual reality this way. If anyone had, he was keeping quiet about it-nothing in the journals, not a whisper on the Web. Justin would have known; he had virbots out prowling all the time. They'd never found anything close. He had this all to himself… if he hadn't been wasting his time.

Up came the field parameters, at long, long last. Justin studied them. As the computer had, he took his time. He didn't want to let enthusiasm run away with him before he was sure. He'd done that half a lifetime ago, and what had it got him? A divorce that had blighted his life ever since. He wouldn't jump too soon. Not again. Not ever again. But things looked good.

"Yes!" he said softly. He'd been saying it that particular way since he was a teenager. He couldn't have named the disgraced sportscaster from whom he'd borrowed it if he'd gone on the rack.

He saved the parameters, quit his application, and had the computer back up everything he'd done. The backup disk went into his briefcase. And then, yawning, he hit the sack.

Three days later, Garth O'Connell was the first to gape when Justin came into the office. "Buzz cut!" he exclaimed, and ran a hand over his own thinning hair. Then he laughed and started talking as if the past twenty years hadn't happened: "Yo, dude. Where's the combat boots?"

In my closet, Justin thought. He didn't say that. What he did say was, "I felt like doing something different, that's all."

"Like what?" Garth asked.

"Globalsearching for high school quail, like the barkeep said? The competition doesn't wear short hair any more, you know."

"Will you melt it down?" Justin snapped.

"Okay. Okay." Garth spread his hands.

"But you better get used to it, 'cause everybody else is gonna say the same kind of stuff."

Odds were he was right, Justin realized gloomily. He grabbed a cup of coffee at the office machine, then ducked into his cubicle and got to work. That slowed the stream of comments, but didn't stop them. People would go by the cubicle, see the side view, do a double take, and start exclaiming.

Inside half an hour, Justin's division head came by to view the prodigy. She rubbed her chin. "Well, I don't suppose it looks unbusinesslike," she said dubiously.

"Thanks, Ms. Chen," Justin said. "I just wanted to-"

"Start your mid-life crisis early." As it had a few evenings before, Sean Peters's voice drifted over the walls of the cubicle.

"And thank you, Sean." Justin put on his biggest grin. Ms. Chen smiled, which meant he'd passed the test. She gave his hair another look, nodded more happily than she'd spoken, and went off to do whatever managers did when they weren't worrying about haircuts.

Sean kept his mouth shut till lunchtime, when he stuck his head into Justin's cubicle and said, "Feel like going over to Omino's? I've got a yen for Japanese food." He laughed. Justin groaned. That made Peters laugh harder than ever.

Justin shook his head. Pointing toward his monitor, he said, "I'm brownbagging it today. Got a ton of stuff that needs doing."

"Okay." Peters shrugged. "Anybody'd think you worked here or something. I'll see you later, then."

Between noon and half past one, Superstrings was nearly deserted. Munching on a salami sandwich and an orange, Justin worked on his own project, his private project.

The office machine was better than his home computer for deciding whether possible meant practical.

"Yes!" he said again, a few minutes later, and then, "Time to go shopping."

Being the sort of fellow he was, he shopped with a list. Vintage clothes came from Aaardvark's Odd Ark, undoubtedly the funkiest secondhand store in town, if not in the world. As with his haircut, he did his best to match the way he'd looked just before the turn of the century.

Old money was easier; he had to pay only a small premium for old-fashioned smallhead bills at the several coin-and-stamp shops he visited. "Why do you want 'em, if you don't care about condition?" one dealer asked.

"Maybe I think the new bills are ugly," he answered. The dealer shrugged, tagging him for a nut but a harmless one. When he got to $150,000, he checked money off the list.

He got to the office very early the next morning. The security guard chuckled as he unlocked the door. "Old clothes and everything. Looks like you're moving in, pal."

"Seems like that sometimes, too, Bill."

Justin set down his suitcases for a moment. "But I'm going out of town this afternoon. I'd rather have this stuff indoors than sitting in the trunk of my car."

"Oh, yeah." Bill nodded. He had to be seventy, but his hair wasn't any lighter than iron gray. "I know that song." He knew lots of songs, many dating back to before Justin was born. He'd fought in Vietnam, and been a cop, and now he was doing this because his pension hadn't come close to keeping up with skyrocketing prices. Justin wondered if his own would, come the day.

But he had different worries now.

"Thanks," he said when the guard held the door for him.

He staggered up the stairs; thanks to the stash of cash (a new compact car here, nothing more, even with the premium he'd had to pay, but a young fortune before the turn of the century), some period clothes scrounged-like the Dilbert T-shirt and baggy jeans he had on-from secondhand stores, and the boots, those suitcases weren't light, and he'd never been in better shape than he could help. The backpack in which he carried his PowerBook and VR mask did nothing to make him more graceful, either.

Once he got up to the second floor, he paused and listened hard. "Yes!" he said when he heard nothing.

Except for Bill down below, he was the only person here.

He went into the men's room, piled one suitcase on the other, and sat down on them. Then he took the laptop out of its case. He plugged the VR mask into its jack, then turned on the computer. As soon as it came up, he put on the mask. The world went black, then neutral gray, then neutral… neutral: no color at all, just virtual reality waiting to be made real.

It all took too long. He wished he could do this back at his desk, with an industrial-strength machine. But he didn't dare take the chance. This building had been here nineteen years ago. This men's room had been here nineteen years ago. He'd done his homework as well as he could. But his homework hadn't been able to tell him where the goddamn cubicle partitions were back before the turn of the century.

And so… the john. He took a deep breath. "Run program superstrings-slash-virtual reality-slash-not so virtual," he said.

The PowerBook quivered, ever so slightly, on his lap. His heart thudded. Talk about your moments of truth.

Either he was as smart as he thought he was, or Garth or Sean or somebody would breeze in and ask, "Justin, what the hell are you doing?"

A string in space-time connected this place now to its earlier self, itself in 1999. As far as Justin knew, nobody but him had thought of accessing that string, of sliding along it, with VR technology. When the simulation was good enough, it became the reality-for a while, anyhow. That was what the math said. He thought he'd done a good enough job here.

And if he had… oh, if he had! He knew a hell of a lot more now, at forty, than he had when he was twenty-one. If he-now could be back with Megan for a while instead of his younger self, he could make things right. He could make things last. He knew it. He had to, if he ever wanted to be happy again.