"Hey, Justin!" Sean Peters's voice floated over the top of the Superstrings, Ltd., cubicle wall. "It's twenty after six-quitting time and then some. Want a drink or two with me and Garth?"

"Hang on," Justin Kloster answered. "Let me save what I'm working on first." He told his computer to save his work as it stood, generate a backup, and shut itself off. Having grown up in the days when voice-recognition software was imperfectly reliable, he waited to make sure the machine followed orders. It did, of course. Making that software idiotproof had put Superstrings on the map a few years after the turn of the century.

Justin got up, stretched, and looked around. Not much to see: the grayish-tan fuzzy walls of the cubicle and an astringently neat desktop that held the computer, a wedding photo of Megan and him, and a phone/fax. His lips narrowed. The marriage had lasted four years-four and a half, actually. He hadn't come close to finding anybody else since.

Footsteps announced Peters's arrival. He looked like a high school linebacker who'd since let most of his muscle go to flab. Garth O'Connell was right behind him. He was from the same mold, except getting thin on top instead of going gray.

"How's the Iron Curtain sound?" Peters asked.

"Sure," Justin said. "It's close, and you can hear yourself think-most of the time, anyhow."

They went out into the parking lot together, bitching when they stepped from air conditioning to San Fernando Valley August heat. Justin's eyes started watering, too; L.A. smog wasn't so bad as it had been when he was young, but it hadn't disappeared.

An Oasis song was playing when the three software engineers walked into the Iron Curtain, and into air conditioning that was chillier than that at the office. The music took Justin back to the days when he'd been getting together with Megan, though he'd liked Blur better. "Look out," Sean Peters said.

"They've got a new fellow behind the bar." He and Garth chuckled.

They knew what was going to happen. Justin sighed. So did he.

Peters ordered a gin and tonic, O'Connell a scotch on the rocks. Justin asked for a Bud. Sure as hell, the bartender said, "I'll be right with you two gents"-he nodded to Justin's coworkers-"but for you, sir, I'll need some ID."

With another sigh, Justin produced his driver's license. "Here."

The bartender looked at him, looked at his picture on the license, and looked at his birthdate. He scowled.

"You were born in 1978? No way."

"His real name's Dorian Gray," Garth said helpfully.

"Oh, shut up," Justin muttered, and then, louder, to the bartender, "Yeah, I really turned forty this past spring." He was slightly pudgy, but he'd been slightly pudgy since he was a toddler. And he'd been very blond since the day he was born. If he had any silver mixed with the gold, it didn't show. He also stayed out of the sun as much as he could, because he burned to a crisp when he didn't. That left him with a lot fewer lines and wrinkles than his buddies, who were both a couple of years younger than he.

Shaking his head, the bartender slid Justin a beer. "You coulda fooled me," he said. "You go around picking up high school girls?" His hands shaped an hourglass in the air.

"No." Justin stared down at the reflections of the ceiling lights on the polished bar.

"Middle school," Garth suggested. He'd already made his scotch disappear. Justin gave him a dirty look. It was such a dirty look, it got through to Sean Peters. He tapped Garth on the arm. For a wonder, Garth eased off.

Justin finished the Bud, threw a twenty on the bar, and got up to leave. "Not going to have another one?"

Peters asked, surprised.

"Nope." Justin shook his head. "Got some things to do. See you in the morning." Out he went, walking fast so his friends couldn't stop him.

* * *

As soon as the microchip inside Justin's deadbolt lock shook hands with the one in his key, his apartment came to life. Lamps came on. The stereo started playing the Pulp CD he'd left in there this morning. The broiler heated up to do the steak the computer knew was in the refrigerator. From the bedroom, the computer called, "Now or later?"

"Later," Justin said, so the screen stayed dark.

He went into the kitchen and tossed a couple of pieces of spam snailmail into the blue wastebasket for recycling. The steak went under the broiler; frozen mixed vegetables went into the microwave. Eight minutes later, dinner.

After he finished, he rinsed the dishes and silverware and put them in the dishwasher. When he closed the door, the light inside came on; the machine judged itself full enough to run a cycle in the middle of the night.

Like the kitchen, his front room was almost as antiseptically tidy as his cubicle at Superstrings. But for a picture of Megan and him on their honeymoon, the coffee table was bare. All his books and DVDs and audio CDs were arranged alphabetically by author, title, or group. None stood even an eighth of an inch out of place. It was as if none of them dared move without his permission.

He went into the bedroom. "Now," he said, and the computer monitor came to life.

A picture of Megan and him stood on the dresser, another on the nightstand. Her high school graduation picture smiled at him whenever he sat down at the desk. Even after all these years, he smiled back most of the time. He couldn't help it. He'd always been happy around Megan.

But she hadn't been happy around him, not at the end. Not for a while before the end, either. He'd been a long, long time realizing that. "Stupid," he said. He wasn't smiling now, even with Megan's young, glowing face looking right at him out of the picture frame. "I was stupid. I didn't know enough. I didn't know how to take care of her."

No wonder he hadn't clicked with any other woman. He didn't want any other woman. He wanted Megan-and he couldn't have her any more.

"E-mail," he told the computer, and gave his password. He went through it, answering what needed answering and deleting the rest. Then he said, "Banking." The computer had paid the monthly Weblink bill, and the cable bill, too. "All good," he told it.

The CD in the stereo fell silent.

"Repeat?" the computer asked.

"No." Justin went out to the front room.

He took the Pulp CD out of the player, put it in its jewel box, and put the jewel box exactly where it belonged on the shelf. Then he stood there in a rare moment of indecision, wondering what to pull out next. When he chose a new CD, he chuckled. He doubted Sean or Garth would have heard of the Trash Can Sinatras, let alone any of their music. His work buddies had listened to grunge rock back before the turn of the century, not British pop.

As soon as Cake started, he went back into the bedroom and sat down at the computer again. This time, he did smile at Megan's picture. She'd been crazy for the Trash Can Sinatras, too.

The music made him especially eager to get back to work. "Superstrings," he said, and gave a password, and "Virtual reality" and another password, and "Not so virtual" and one more. Then he had to wait. He would have killed for a Mac a quarter this powerful back in 1999, but it wasn't a patch on the one he used at the office. The company could afford the very best. He couldn't, not quite.

He went to the keyboard for this work: for numbers, it was more precise than dictating. And he had to wait again and again while the computer did the crunching. One wait was long enough for him to go take a shower. When he got back, hair still damp, the machine hadn't finished muttering to itself. Justin sighed. But the faster Macs at the office couldn't leap these numbers at a single bound. What he was asking of his home computer was right on the edge of what it could do.

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.

I'll fix it, he thought. I'll fix everything. And when I slide back to here-and-now, I won't have this emptiness in my past.

Everything will be the way it could have been, the way it should have been.

An image began to emerge from the VR blankness. It was the same image he'd seen before slipping on the mask: blue tile walls with white grouting, acoustic ceiling, sinks with a mirror above them, urinals off to the left, toilet stalls behind him.

"Dammit," he muttered under his breath.

Sure as hell, the men's room hadn't changed at all.

"Program superstrings-slash-virtual reality-slash-not so virtual reality is done," the PowerBook told him.

He took off the mask. Here he sat, on his suitcases, in the men's room of his office building. 2018? 1999? He couldn't tell, not staying in here. If everything had worked out the way he'd calculated, it would be before business hours back when he'd arrived, too. All he had to do was walk out that front door and hope the security guard wasn't right there.

No. What he really had to hope was that the security guard wasn't Bill.

He put the computer in his backpack again. He picked up the suitcases and walked to the men's-room door.

He set down a case so he could open the door. His heart pounded harder than ever. Yes? Or no?

* * *

Justin took two steps down the hall toward the stairs before he whispered, "Yes!" Instead of the gray-green carpet he'd walked in on, this stuff was an ugly mustard yellow. He had no proof he was in 1999, not yet. But he wasn't in Kansas any more.

The place had the quiet-before-the-storm feeling offices get waiting for people to show up for work. That fit Justin's calculations. The air conditioner was noisier, wheezier, than the system that had been-would be-in his time. But it kept the corridor noticeably cooler than it had been when he lugged his stuff into the men's room. The 90s had ridden an oil glut. They burned lavishly to beat summer heat. His time couldn't.

There was the doorway that led to the stairs. Down he went. The walls were different: industrial yellow, not battleship gray. When he got to the little lobby, he didn't recognize the furniture. What was there seemed no better or worse than what he was used to, but it was different.

If there was a guard, he was off making his rounds. Justin didn't wait for him. He opened the door. He wondered if that would touch off the alarm, but it didn't. He stepped out into the cool, fresh early-morning air of… when?

He walked through the empty lot to the sidewalk, then looked around. Across the street, a woman out power-walking glanced his way, but didn't stop. She wore a cap, a T-shirt, and baggy shorts, which proved nothing. But then he looked at the parked cars, and began to grin a crazy grin. Most of them had smooth jelly-bean lines, which, to his eyes, was two style changes out of date. If this wasn't 1999, it was damn close.

With a clanking rumble of iron, a MetroLink train pulled into the little station behind his office. A couple of people got off; a handful got on. In his day, with gas ever scarcer, ever costlier, that commuter train would have far more passengers.

Standing on the sidewalk, unnoticed by the world around him, he pumped a fist in the air. "I did it!" he said. "I really did it!"

Having done it, he couldn't do anything else, not for a little while. Not much was open at half-past five.

But there was a Denny's up the street. Suitcases in hand, he trudged toward it. The young, bored-looking Hispanic waitress who seated him gave him a fishy stare. "You coulda left your stuff in the car," she said pointedly.

His answer was automatic: "I don't have a car." Her eyebrows flew upward. If you didn't have a car in L.A., you were nobody. If you didn't have a car and did have suitcases, you were liable to be a dangerously weird nobody. He had to say something. Inspiration struck: "I just got off the train. Somebody should've picked me up, but he blew it. Toast and coffee, please?"

She relaxed. "Okay-coming up. White, rye, or whole wheat?"

"Wheat." Justin looked around. He was the only customer in the place. "Can you keep an eye on the cases for a second? I want to buy a Times." He'd seen the machine out front, but hadn't wanted to stop till he got inside. When the waitress nodded, he got a paper. It was only a quarter. That boggled him; he paid two bucks weekdays, five Sundays.

But the date boggled him more. June 22, 1999. Right on the money. He went back inside. The coffee waited for him, steaming gently. The toast came up a moment later.

As he spread grape jam over it, he glanced at the Times and wondered what his younger self was doing now.

Sleeping, you dummy. He'd liked to sleep late when he was twenty-one, and finals at Cal State Northridge would have just ended. He'd have the CompUSA job to go to, but the place didn't open till ten.

Megan would be sleeping, too. He thought of her lying in a T-shirt and sweats at her parents' house, wiggling around the way she did in bed. Maybe she was dreaming of him and smiling. She would be smiling now. A few years from now… well, he'd come to fix that.

He killed forty-five minutes. By then, the restaurant was filling up. The waitress started to look ticked.

Justin ordered bacon and eggs and hash browns. They bought him the table for another hour. He tried not to think about what the food was doing to his coronary arteries. His younger self wouldn't have cared. His younger self loved Denny's. My younger self was a fool, he thought.

He paid, again marveling at how little things cost. Of course, people didn't make much, either; you could live well on $100,000 a year. He tried to imagine living on $100,000 in 2018, and shook his head. You couldn't do it, not if you felt like eating, too.

When he went out to the parking lot, he stood there for forty minutes, looking back toward the train station. By then, it was getting close to eight o'clock. Up a side street from the Denny's was a block of apartment buildings with names like the Tivoli, the Gardens, and the Yachtsman. Up the block he trudged. The Yachtsman had a vacancy sign.

The manager looked grumpy at getting buzzed so early, but the sight of greenbacks cheered him up in a hurry. He rented Justin a one-bedroom furnished apartment at a ridiculously low rate. "I'm here on business," Justin said, which was true… in a way. "I'll pay three months in advance if you fix me up with a TV and a stereo. They don't have to be great. They just have to work."

"I'd have to root around," the manager said. "It'd be kind of a pain." He waited. Justin passed him two fifties. He nodded. So did Justin. This was business, too. The manager eyed his suitcases. "You'll want to move in right away, won't you?"

Justin nodded again. "And I'll want to use your phone to set up my phone service."

"Okay," the manager said with a sigh.

"Come into my place here. I'll get things set up." His fish-faced wife watched Justin with wide, pale, unblinking eyes while he called the phone company and made arrangements. The manager headed off with a vacuum cleaner. In due course, he came back. "You're ready. TV and stereo are in there."

"Thanks." Justin went upstairs to the apartment. It was small and bare, with furniture that had seen better decades. The TV wasn't new. The stereo was so old, it didn't play CDs, only records and cassettes. Well, his computer could manage CDs. He accepted a key to the apartment and another for the security gates, then unpacked. He couldn't do everything he wanted till he got a phone, but he was here.

* * *

He used a pay phone to call a cab, and rode over to a used car lot. He couldn't do everything he wanted without wheels, either. He had no trouble proving he was himself; he'd done some computer forgery before he left to make his driver's license expire in 2003, as it really did. His number hadn't changed.

Security holograms that would have given a home machine trouble here-and-now were a piece of cake to graphics programs from 2018.

His younger self didn't know he'd just bought a new old car: a gray early- 90s Toyota much like the one he was already driving.

"Insurance is mandatory," the salesman said. "I can sell you a policy…" Justin let him do it, to his barely concealed delight. It was, no doubt, highway robbery, especially since Justin was nominally only twenty-one. He'd dressed for the age he affected, in T-shirt and jeans. To him, though, no 1999 prices seemed expensive. He paid cash and took the car.

Getting a bank account wasn't hard, either. He chose a bank his younger self didn't use. Research paid off: he deposited only $9,000. Ten grand or more in cash and the bank would have reported the transaction to the government. He didn't want that kind of notice. He wanted no notice at all. The assistant manager handed him a book of temporary checks. "Good to have your business, Mr. Kloster. The personalized ones will be ready in about a week."

"Okay." Justin went off to buy groceries.

He wasn't a great cook, but he was a lot better than his younger self. He'd had to learn, and had.

Once the groceries were stowed in the pantry and the refrigerator, he left again, this time to a bookstore. He went to the computer section first, to remind himself of the state of the art. After a couple of minutes, he was smiling and shaking his head. Had he done serious work with this junk? He supposed he had, but he was damned if he saw how. Before he was born, people had used slide rules because there weren't any computers yet, or even calculators. He was damned if he saw how they'd done any work, either.

But the books didn't have exactly what he wanted. He went to the magazine rack. There was a MacAddict in a clear plastic envelope. The CD-ROM that came with the magazine would let him start an account on a couple of online services. Once he had one, he could e-mail his younger self, and then he'd be in business.

If I-or I-then-don't flip out altogether, he thought. Things might get pretty crazy. Now that he was here and on the point of getting started, he felt in his belly how crazy they might get. And he knew both sides of things. His younger self didn't.

Would Justin-then even listen to him? He had to hope so. Looking back, he'd been pretty stupid when he was twenty-one. No matter how stupid he'd been, though, he'd have to pay attention when he got his nose rubbed in the facts. Wouldn't he?

Justin bought the MacAddict and took it back to his apartment. As soon as he got online, he'd be ready to roll.

* * *

He chose AOL, not Earthlink. His younger self was on Earthlink, and looked down his nose at AOL. And AOL let him pay by debiting his checking account. He didn't have any credit cards that worked in 1999. He supposed he could get one, but it would take time. He'd taken too much time already. He thought he had about three months before the space-time string he'd manipulated would snap him back to 2018. With luck, with skill, with what he knew then that he hadn't known now, he'd be happier there. But he had no time to waste.

His computer, throttled down to 56K access to the outside world, might have thought the same. But AOL's local access lines wouldn't support anything faster. "Welcome," the electronic voice said as he logged on. He ignored it, and went straight to e-mail. He was pretty sure he remembered his old e-mail address. If I don't, he thought, chuckling a little as he typed, whoever is using this address right now will get awfully confused.

He'd pondered what he would say to get his younger self's attention, and settled on the most provocative message he could think of. He wrote, Who but you would know that the first time you jacked off, you were looking at Miss March 1993, a little before your fifteenth birthday? Nobody, right? Gorgeous blonde, wasn't she? The only way I know that is that I am you, more or less. Let me hear from you. He signed it, Justin Kloster, age 40, and sent it.

Then he had to pause. His younger self would be working now, but he'd check his e-mail as soon as he got home. Justin remembered religiously doing that every day. He didn't remember getting e-mail like the message he'd just sent, of course, but that was the point of this exercise.

Waiting till half past five wasn't easy.

He wished he could use his time-travel algorithm to fast-forward to late afternoon, but he didn't dare. Too many superstrings might tangle, and even the office machine up in 2018 hadn't been able to work out the ramifications of that. In another ten years, it would probably be child's play for a computer, but he wouldn't be able to pretend he was twenty-one when he was fifty. Even a baby face and pale gold hair wouldn't stretch that far. He hoped they'd stretch far enough now.

At 5:31, he logged onto AOL again.

"Welcome!" the voice told him, and then, "You've got mail!"

"You've got spam," he muttered under his breath. And one of the messages in his mailbox was spam. He deleted it without a qualm. The other one, though, was from his younger self @earthlink.net.

Heart pounding, he opened the e-mail.

What kind of stupid joke is this? his younger self wrote.

Whatever it is, it's not funny.

Justin sighed. He supposed he shouldn't have expected himself-at-twenty-one to be convinced right away. This business was hard to believe, even for him. But he had more shots in his gun than one. No joke, he wrote back. Who else but you would know you lost your first baby tooth in a pear at school when you were in the first grade? Who would know your dad fed you Rollos when he took you to work with him that day you were eight or nine?

Who would know you spent most of the time while you were losing your cherry staring at the mole on the side of Lindsey Fletcher's neck?

Me, that's who: you at 40. He typed his name and sent the message.

His stomach growled, but he didn't go off and make supper. He sat by the computer, waiting. His younger self would still be online. He'd have to answer… wouldn't he? Justin hadn't figured out what he'd do if himself-at-twenty-one wanted nothing to do with him. The prospect had never crossed his mind.

Maybe it should have.

"Don't be stupid, kid," he said softly.

"Don't complicate things for me. Don't complicate things for yourself, either."

He sat. He waited. He worried. After what seemed forever, but was less than ten minutes, the AOL program announced, "You've got mail!"

He read it. I don't watch X-Files much, his younger self wrote, but maybe I ought to. How could you know all that about me? I never told anybody about Lindsey Fletcher's neck.

So far as Justin could recall, he hadn't told anyone about her neck by 2018, either. That didn't mean he'd forgotten. He wouldn't forget till they shoveled dirt over him.

How do I know? he wrote. I've told you twice now-I know because I am you, you in 2018. It's not X-Files stuff-it's good programming. The show still ran in endless syndication, but he hadn't watched it for years. He went on, Believe me, I'm back here for a good reason, and sent the e-mail.

Again, he waited. Again, the reply came back fast. He imagined his younger self eyeing the screen of his computer, eyeing it and scratching his head. His younger self must have been scratching hard, for what came back was, But that's impossible.

Okay, he typed. It's impossible. But if it is impossible, how do I know all this stuff about you?

More waiting. The hell with it, he thought. He'd intended to broil lamb chops, but he would have had to pay attention to keep from cremating them. He took a dinner out of the freezer and threw it into the tiny microwave built in above the stove. He could punch a button and get it more or less right. Back to the computer.

"You've got mail!" it said once more, and he did. I don't know, his younger self had written.

How do you know all this stuff about me?

Because it's stuff about me, too, he answered. You don't seem to be taking that seriously yet.

The microwave beeped. Justin started to go off to eat, but the PowerBook told him he had more mail. He called it up. If you're supposed to be me, himself-at-twenty-one wrote, then you'll look like me, right?

Justin laughed. His younger self wouldn't believe that. He'd probably think it would make this pretender shut up and go away. But Justin wasn't a pretender, and didn't need to shut up-he could put up instead. Right, he replied. Meet me in front of the B. Dalton's in the Northridge mall tomorrow night at 6:30 and I'll buy you dinner. You'll see for yourself. He sent the message, then did walk away from the computer.

Eating frozen food reminded him why he'd learned to cook. He chucked the tray into the trash, then returned to the bedroom to see what his younger self had answered. Three words: See you there.

* * *

The mall surprised Justin. In his time, it had seen better years. In 1999, just a little after being rebuilt because of the 94 earthquake, it still seemed shiny and sparkly and new. Justin got there early. With his hair short, with the Cow Pi T-shirt and jeans and big black boots he was wearing, he fit in with the kids who shopped and strutted and just hung out.

He found out how well he fit when he eyed an attractive brunette of thirty or so who was wearing business clothes. She caught him doing it, looked horrified for a second, and then stared through him as if he didn't exist. At first, he thought her reaction was over the top. Then he realized it wasn't. You may think she's cute, but she doesn't think you are. She thinks you're wet behind the ears.

Instead of leaving him insulted, the woman's reaction cheered him. Maybe I can bring this off.

He leaned against the brushed-aluminum railing in front of the second-level B. Dalton's as if he had nothing better to do. A gray-haired man in maroon polyester pants muttered something about punk kids as he walked by. Justin grinned, which made the old fart mutter more.

But then the grin slipped from Justin's face. What replaced it was probably astonishment. Here came his younger self, heading up from the Sears end of the mall.

He could tell the moment when his younger self saw him. Himself-at-twenty-one stopped, gaped, and turned pale.

He looked as if he wanted to turn around and run away. Instead, after gulping, he kept on.

Justin's heart pounded. He hadn't realized just how strange seeing himself would feel. And he'd been expecting this. For his younger self, it was a bolt from the blue.

That meant he had to be the one in control. He stuck out his hand.

"Hi," he said. "Thanks for coming."

His younger self shook hands with him.

They both looked down. The two right hands fit perfectly. Well, they would, wouldn't they? Justin thought. His younger self, still staring, said, "Maybe I'm not crazy. Maybe you're not crazy, either. You look just like me."

"Funny how that works," Justin said.

Seeing his younger self wasn't like looking in a mirror. It wasn't because himself-at-twenty-one looked that much younger-he didn't. It wasn't even because his younger self wasn't doing the same things he did. After a moment, he figured out what it was: his younger self's image wasn't reversed, the way it would have been in a mirror. That made him look different.

His younger self put hands on hips.

"Prove you're from the future," he said.

Justin had expected that. He took a little plastic coin purse, the kind that can hook onto a key chain, out of his pocket and squeezed it open. "Here," he said. "This is for you." He handed himself-at-twenty-one a quarter.

It looked like any quarter-till you noticed the date. "It's from 2012," his younger self whispered. His eyes got big and round again. "Jesus. You weren't kidding."

"I told you I wasn't," Justin said patiently. "Come on. What's the name of that Korean barbecue place on… Reseda?" He thought that was right. It had closed a few years after the turn of the century.

His younger self didn't notice the hesitation. "The Pine Tree?"

"Yeah." Justin knew the name when he heard it. "Let's go over there. I'll buy you dinner, like I said in e-mail, and we can talk about things."

"Like what you're doing here," his younger self said.

He nodded. "Yeah. Like what I'm doing here."

* * *

None of the waitresses at the Pine Tree spoke much English. That was one reason Justin had chosen the place: he didn't want anybody eavesdropping. But he liked garlic, he liked the odd vegetables, and he enjoyed grilling beef or pork or chicken or fish on the gas barbecue set into the tabletop.

He ordered for both of them. The waitress scribbled on her pad in the odd characters of hangul, then looked from one of them to the other. "Twins," she said, pulling out a word she did know.

"Yeah," Justin said. Sort of, he thought. The waitress went away.

His younger self pointed at him. "Tell me one thing," he said.

"What?" Justin asked. He expected anything from What are you doing here? to What is the meaning of life?

But his younger self surprised him: "That the Rolling Stones aren't still touring by the time you're-I'm-forty."

"Well, no," Justin said. That was a pretty scary thought, when you got down to it. He and his younger self both laughed. They sounded just alike. We would, he thought.

The waitress came back with a couple of tall bottles of OB beer. She hadn't asked either one of them for an ID, for which Justin was duly grateful. His younger self kept quiet while she was around. After she'd gone away, himself-at-twenty-one said, "Okay, I believe you. I didn't think I would, but I do. You know too much-and you couldn't have pulled that quarter out of your ear from nowhere." He sipped at the Korean beer. He looked as if he would sooner have gone out and got drunk.

"That's right," Justin agreed. Stay in control. The more you sound like you know what you're doing, the more he'll think you know what you're doing. And he has to think that, or this won't fly.

His younger self drank beer faster than he did, and waved for a second tall one as soon as the first was empty. Justin frowned. He remembered drinking more in his twenties than he did at forty, but didn't care to have his nose rubbed in it.

He wouldn't have wanted to drive after two big OBs, but his younger self didn't seem to worry about it.

With his younger self's new beer, the waitress brought the meat to be grilled and the plates of vegetables. She used aluminum tongs to put some pork and some marinated beef over the fire. Looking at the strips of meat curling and shrinking, himself-at-twenty-one exclaimed, "Oh my God! They killed Kenny!"

"Huh?" Justin said, and then, "Oh." He managed a feeble chuckle. He hadn't thought about South Park in a long time.

His younger self eyed him. "If you'd said that to me, I'd have laughed a lot harder. But the show's not hot for you any more, is it?" He answered his own question before Justin could: "No, it wouldn't be. 2018? Jesus." He took another big sip of beer.

Justin grabbed some beef with the tongs.

He used chopsticks to eat, ignoring the fork. So did his younger self. He was better at it than himself-at-twenty-one; he'd had more practice. The food was good. He remembered it had been.

After a while, his younger self said, "Well, will you tell me what this is all about?"

"What's the most important thing in your life right now?" Justin asked in return.

"You mean, besides trying to figure out why I'd travel back in time to see me?" his younger self returned.

He nodded, carefully not smiling. He'd been looser, sillier, at twenty-one than he was now. Of course, he'd had fewer things go wrong then, too. And his younger self went on, "What could it be but Megan?"

"Okay, we're on the same page," Justin said. "That's why I'm here, to set things right with Megan."

"Things with Megan don't need setting right." Himself-at-twenty-one sounded disgustingly complacent.

"Things with Megan are great. I mean, I'm taking my time and all, but they're great. And they'll stay great, too. How many kids do we have now?"

"None." Justin's voice went flat and harsh. A muscle at the corner of his jaw jumped. He touched it to try to calm it down.

"None?" His younger self wasn't quick on the uptake. He needed his nose rubbed in things. He looked at Justin's left hand. "You're not wearing a wedding ring," he said.

He'd just noticed. Justin's answering nod was grim. His younger self asked, "Does that mean we don't get married?"

Say it ain't so. Justin did: "We get married, all right. And then we get divorced."

His younger self went as pale as he had when he first saw Justin. Even at twenty-one, he knew too much about divorce. Here-and-now, his father was living with a woman not much older than he was. His mother was living with a woman not much older than he was, too. That was why he had his own apartment: paying his rent was easier for his mom and dad than paying him any real attention.

But, however much himself-at-twenty-one knew about divorce, he didn't know enough. He'd just been a fairly innocent bystander. He hadn't gone through one from the inside. He didn't understand the pain and the emptiness and the endless might-have-beens that kept going through your mind afterward.

Justin had had those might-have-beens inside his head since he and Megan had fallen apart. But he was in a unique position, sitting here in the Pine Tree eating kimchi.

He could do something about them.

He could. If his younger self let him.

Said younger self blurted, "That can't happen."

"It can. It did. It will," Justin said.

The muscle started twitching again.

"But-how?" Himself-at-twenty-one sounded somewhere between bewildered and shocked. "We aren't like Mom and Dad-we don't fight all the time, and we don't look for something on the side wherever we can find it." Even at twenty-one, he spoke of his parents with casual contempt. Justin thought no better of them in 2018.

He said, "You can fight about sex, you can fight about money, you can fight about in-laws. We ended up doing all three, and so…" He set down his chopsticks and spread his hands wide. "We broke up-will break up-if we don't change things. That's why I figured out how to come back: to change things, I mean."

His younger self finished the second OB.

"You must have wanted to do that a lot," he remarked.

"You might say so." Justin's voice came harsh and ragged. "Yeah, you just might say so. Since we fell apart, I've never come close to finding anybody who makes me feel the way Megan did. If it's not her, it's nobody. That's how it looks from here, anyhow. I want to make things right for the two of us."

"Things were going to be right."

But his younger self lacked conviction. Justin sat and waited. He was better at that than he had been half a lifetime earlier.

Finally, himself-at-twenty-one asked, "What will you do?"

He didn't ask, What do you want to do? He spoke as if Justin were a force of nature. Maybe that was his youth showing. Maybe it was just the beer. Whatever it was, Justin encouraged it by telling his younger self what he would do, not what he'd like to do: "I'm going to take over your life for a couple of months. I'm going to be you. I'm going to take Megan out, I'm going to make sure things are solid-and then the superstring I've ridden to get me here will break down. You'll live happily ever after: I'll brief you to make sure you don't screw up what I've built. And when I get back to 2018, I will have lived happily ever after. How does that sound?"

"I don't know," his younger self said.

"You'll be taking Megan out?"

Justin nodded. "That's right."

"You'll be… taking Megan back to the apartment?"

"Yeah," Justin said. "But she'll think it's you, remember, and pretty soon it'll be you, and it'll keep right on being you till you turn into me, if you know what I mean."

"I know what you mean," his younger self said. "Still…" He grimaced. "I don't know. I don't like it."

"You have a better idea?" Justin folded his arms across his chest and waited, doing his best to be the picture of inevitability. Inside, his stomach tied itself in knots.

He'd always been better at the tech side of things than at sales.

"It's not fair," himself-at-twenty-one said. "You know all this shit, and I've gotta guess."

Justin shrugged. "If you think I did all this to come back and tell you lies, go ahead. That's fine." It was anything but fine. But he couldn't let his younger self see that.

"You'll see what happens, and we'll both be sorry."

"I don't know." His younger self shook his head, again and again. His eyes had a trapped-animal look. "I just don't know. Everything sounds like it hangs together, but you could be bullshitting, too, just as easy."

"Yeah, right." Justin couldn't remember the last time he'd said that, but it fit here.

Then his younger self got up. "I won't say yes and I won't say no, not now I won't. I've got your e-mail address. I'll use it." Out he went, not quite steady on his feet.

Justin stared after him. He paid for both dinners-it seemed like peanuts to him-and went home himself. His younger self needed time to think things through. He saw that.

Seeing it and liking it were two different things. And every minute himself-at-twenty one dithered was a minute he couldn't get back. He stewed. He fumed. He waited. What other choice did he have?

You could whack him and take over for him. But he rejected the thought with a shudder. He was no murderer. All he wanted was some happiness. Was that too much to ask? He didn't think so, not after all he'd missed since Megan made him move out. He checked his e-mail every hour on the hour.