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.