He did that, or tried to. It was hard to get their attention, for two reasons: the operations team was still probing in and around the era with their time-scan tanks and things were clearing up a little, and ... well, he was a robot. Most people were astonished that he was there. It was as if my refrigerator had come into Operations, tap-dancing and singing Suwannee, wearing a sandwich board proclaiming the end of the world.

But he managed to tell them. Simultaneously, or a few seconds later, depending on who you believe, one of the operatives spotted Bill Smith in a helicopter returning from the 747 crash site and someone else found the same helicopter parked on the apron outside the hangar I was visiting. Inference: Smith and I could meet inside that hangar.

That's when they started listening to Sherman. It was a matter of a few seconds to confirm that he had indeed received a time capsule, at which point his stock went up tremendously. I'd recently experienced the same effect. Me and my people tend to listen to somebody who's just received a message from the future.

And of course that's when he started to clam up.

"The message was quite specific," he said. "There are certain things I can tell you, and others things chat I must keep secret."

"Come on," I said. "Don't bullshit a bullsh -- " That's as far as I got, and wished I'd buttoned my lip about five syllables earlier. I remembered my suspicion that the Council might be listening in, and the recent time-capsule-inspired performance I'd given them to get this operation authorized.

"There are a few more things I can say," Sherman went on. "The first is that my message confirmed yours, Louise. It said this operation is vital to the success of the Gate Project." He glanced at me, and I wished I had more experience at reading his eyes, but you can't read what isn't there. His new eyes were fake, of course, but looked very natural. His mouth was just a sketch. It could convey expression in the same way a cartoon can. He hadn't bothered with a nose.

"The second thing concerns the next phase, since we all agree the excursion back to window A was of no use."

So the subject was back to windows. What we had was B,C, and D. I thought D was too dangerous, B too unlikely to produce results, and C ...

Tell him about the kid. She's just a wimp.

Nobody knew it but me, but I wasn't going back to Window C. I took a deep breath, got ready to do a cowardly thing, which was to put all my weight behind a trip back to B. I was pretty sure Martin would vote with me, and I thought I could swing Lawrence. The one thing I was sure of was that nobody would go for D. D was the site of the paradox, and surely too dangerous to visit.

"The third thing I can tell you now," Sherman went on, "is that the next visit must be to 2300 hours, Pacific time, on the night of the 13th of December. This is the window you have referred to as D. And Louise should lead the operation."

Testimony of Bill Smith

There was one of those stand-up places not too far away from our conference room. We went in there because we didn't think we'd have time for much more than that. I've seen those places in airports from LAX to Orly, and I've always wondered why people would want to stand up to eat their stale hot dogs. I guess the answer was obvious: they were in a hurry, like us.

I got something they claimed was roast beef, then I spent a lot of time tearing open and squeezing those little packets of mustard and ketchup and some unidentifiable white sauce to kill the gluey taste of the meat. Tom got a chili dog he had to eat with a plastic fork.

"Have you heard that story before?" I asked him.

"Some of it. I had some idea that's what he'd say."

"What'd you think of it?"

Tom took some time with his answer. I was interested, because ground control and operations was his specialty, and he knows a lot about electronics in general -- an area I'll admit isn't my strongest. He was an M.I.T. graduate in computer science, whereas I was a member of the last generation who still knew what a slide rule looked like. You have to know something about computers in my line of work, and I did, but I'd never grown to love them.

"It could happen," he said, at last.

"Do you think it did?"

"I believed him, if that's what you're asking. We may even get corroboration out of the computer. It'll take some work."

I chewed that over. -- "Okay. Assuming it's true. Who do you think we hang for it?"

"What, are you asking for a guess?"

"Why not?"

"Hell, I don't know if we can hang anybody at all. It's early, you understand. There may be something we can turn up that'll -- "

"Off the record, Tom."

He nodded. "Right. We still might not find anybody to blame."

"Listen, Tom. If a tornado springs out of a clear blue sky and wrecks a plane, I'll concede it wasn't anybody's fault. If a meteor falls on a plane, we probably couldn't have done anything about it. If -- "

"Spare me the speech," he said. "I've heard it. What if it turns out that the people to blame are us? You and me and the Board."

"It's been me. It'll be me again." I didn't go on, because he knew what I was talking about.

Sometimes we can't find out exactly what went wrong and you never know if it's just because you didn't look hard enough. Then again, sometimes you find the cause, put it in the report, tell the folks who are supposed to fix it, and they don't fix it. You keep after them to do something about it, but you'll never know if you pushed them hard enough. Did you really go to the wall over it, and was it worth risking your job for ... and so forth. So far there'd never been a dear-cut case where a plane had crashed because I'd overlooked something, let something go that I should have done. But there were any number of crashes that left me wondering if I'd pushed just a little bit harder ...

"Eli said he's seen this before," Tom said.

"Did he report it?" I mean, Eli was a friend, but there are limits.

"He says he did. He's only seen it once, but he's heard of two or three more times it's happened. It's just been such a small problem that nobody's gotten around to doing anything.

You know, the problem of the old computers in general outweighs this glitch in particular.

There's a file on it back in Washington."

"You've seen it?"

"Yeah. I've even fiddled with a solution, but I don't know if it'd work. Short of getting new hardware."

"What does that mean?"

"It's a one-in-a-million thing. It can happen when two planes are in the same section of the sky and the same distance from the radar dish. The ground station queries the on-board transponders, and they respond, and the signals get to the ground at the same time. It's got to be real close; thousandths of a second. And then, sometimes, the computer can't handle it.

They mistake the signals and put the wrong numbers up on the screen. It's garbage in, garbage out."

I knew what he was talking about, but I wasn't sure he was right. Computers, contrary to what you may have been told, are not smart. They're just fast. They can be programmed to act smart, but then it's the programmer who's actually smart and not the computer. If you give a computer long enough to chew on a problem it will usually solve it. And since a long time to a computer is about a millionth of a second, they give the illusion of being smart.

"Okay," I said. "So the information the computer got was garbage, or at least misleading.

An ATC computer shouldn't accept information that's obvious garbage."