"Yes, I am. For two reasons. If we do nothing, the cumulative effects of this thing are going to work their way up the timeline. I believe I was told the rate of approach of this ... one of the engineers called it a "timequake" ... is on the order of two hundred years per hour.

If you can make sense out of a figure like that. I -- "

"We are familiar with the concept," Teheran chided me. "When the timequake arrives here where the disturbance originated, the readjustment in reality will take place all up and down the timeline."

"And we'll all be edited out of it," I finished for him. "Us, and all the effects of our work.

A hundred thousand rescued humans will reappear on falling airplanes, in sinking ships and exploding factories and on battlefields and in the bottom of mineshafts. The Gate Project will be over. I don't suppose it will matter to us since we won't be around to witness it. We'll be never-born."

"There are other theories," The Nameless One said.

"I'm aware of that. Yet in five hundred years of snatch operations no one has suggested we rely on any of them. A few hours ago I let a girl die because it has been so strongly impressed on me that we must treat this theory as if it were proven fact. Are you telling me we're changing theories now?" Do it, you impossible obscenity; tell me that, and I'll find you, and find a way to make you hurt.

"No," it said. "Get on with it. You mentioned a second reason for undertaking this project."

"Which, in my opinion," Teheran added, "might well produce the very temporal catastrophe we are trying to avoid."

"I have to defer to your judgement on that," I said. "I suspect it may be true, myself.

However. The second reason has to do with the time capsule message I opened and read two days ago."

That got a stir out of them. Who says we highly evolved future types aren't superstitious? That message was in my handwriting. That meant I was going to write it when I was a little older, and presumably a little wiser.

But just as cynical. The message had said: "I don't know if it is [vital], but tell them anyway."

There had been no need for her/me to add "don't let anybody see this message." A con like that wouldn't work if anybody but me had seen it.

So I said, "The message said this mission is vital to the success of the Gate Project." And I sat back, not pushing.

Sure enough, in twenty minutes I had the authorization I needed.

There were four days to consider: the tenth through the thirteenth of December. During those four days the Gate had made/would make six different appearances.

The first was my entrance on the 10th, in the New York motel.

The second was actually many trips, carefully spaced, from the afternoon through the evening and early night of the 11th, during the flights of the two aircraft. Both these periods were now closed to us. It hardly mattered: both periods were before the loss of the stunner.

The planes crashed at 9:11 P.m., Pacific Standard Time. The first temporal blank after that was from eight to nine AM. on the following morning, the 12th. We decided to call that Window A, since it was the first period we knew we had not yet stet the Gate to -- which meant we would do so some day.

The second window -- which we called, with fine lack of imagination, B -- was later that same day, from two to four in the afternoon.

Window C was a long one. It started at nine in the evening on the 12th, and went all the way to ten in the morning the next day.

And Window D was the paradox window. It coincided with Smith's visit to the hangar on the night of the 13th.

Each of these windows had advantages and disadvantages.

A was far enough, downtime from the paradox that Smith would be unlikely to be alert to anything. Our research showed that at the time of Window A the wreckage of both planes was, in large part; already in the hangar. If we used that window, it would be m an attempt to find the stunner in the unsorted wreckage and bring it back. If we could do that, all our troubles were over.

B seemed the least promising. What was happening at that time, most probably, was the first playing of the cockpit tape from the 747. I figured I'd go back to that one if and when my first option failed, as it still involved the least interference possible.

As for Window C ...

I was the only one who had read the time capsule message, and even that early in the preparations I had developed a dread for C. I couldn't tell you why. I just know that I felt very bad when I thought of going back and spending a night in Oakland. Tell him about the kid.

She's only a wimp.

No thank you.

Coventry argued for D. Take the bull by the horns, was his feeling. I wondered if he'd started seeing himself as Lars, Cleaver-of-Heads -- a man of action if there ever was one -- instead of an historian. And I wondered if he'd feel the same way if he was the one going back to confront the site of a paradox.

Again, no thank you.

I voted for A, and by voting very hard and as often as I could, eventually got my way. I further decided the expedition should be as small as possible: that is, one person. Coventry had to admit the wisdom of this. When messing with the timestream, you push as gently as possible.

And when you want to be sure a job is done right, there is only one possible person you can send.

At the rate of two hundred years per hour, we had just over eight days to work on the problem. It was not a lot of time. On the e other hand, it was enough that I felt I should use every advantage available to me. So instead of hopping through the Gate to the morning of December 12th and simply sifting through the rubble, I decided to take the time to get an education.

It was ten hours well spent.

What I did was undergo extensive data dumping into the three temporary cybernetic memories implanted in my brain. The BC took everything it had in storage concerning the twentieth century up to the early eighties and unloaded it into my cerebral microprocessors.

I shouldn't make fun of the mental capacities of twentieth-century natives. They did the best they could with what they had. In five hundred centuries the human brain had evolved a little -- I could learn a language the conventional way in about two days -- but the qualitative change was not much. A good comparison might be the times clocked for running the mile. At one time four minutes seemed unreachable. Later, it was routine, and people were shooting for three and a half. But nobody was planning to do it in two seconds flat.

Still, traveling a mile in one second is no problem if you have the help of a jet engine.

In the same way, learning to speak Swahili in one minute or soaking up the contents of a library in an hour is no special trick if you have the appropriate data storage, sorting, and access facilities built into your head.

It's a great tool. You learn to speak a language idiomatically, like a native, and you get a great deal of cultural context in which to speak it.

Those three tiny crystalline memories soaked up encyclopedias, news, movies, television shows, fads, fantasies, and fallacies with equal facility. When I was done I had the lore of a century at my fingertips. I could feel right at home in the 1980s.

Like any tool, the cyber-booster had its drawbacks. It was better at language and facts than it was at pattern recognition. I still would not be able to look at a dress and know, as a native would, whether it came from 1968 or 1978. I could move through the twentieth century with reasonable assurance. If I stayed there very long I'd surely pull some anachronistic boner.