“Is this Papago stuff?” I asked.

“I doubt it. I’m still checking, but I’m sure it’s too good for the Papagos. My guess is that it’s a colony of ancestral Hopis, say a thousand years back, coming downstate out of Kayenta. Shirley’s supposed to bring me some tapes on archaeology next time she goes into Tucson. The data library doesn’t have any of the really advanced texts.”

“You could request them,” I said. “It wouldn’t be hard for the Tucson library to transfer facsims to the dataphone people and shoot them right out to you. If Tucson doesn’t have the right books, they can scoop them from L.A. The whole idea of this data network is that you can get what you need at home, right away, when—”

“I know,” Jack said gently. “But I didn’t want to start too much of a fuss. The next thing you know, I might have a team of archaeologists out here. We’ll get our books the old-fashioned way, by going to the library.”

“How long have you known about this site?”

“A year,” he said. “There’s no hurry.”

I envied him his freedom from all normal pressures. How had these two done it, finding a life like this for themselves in the desert? For one jealous moment I wished it were possible for me to do the same. But I could hardly stay permanently with them, though they might not object, and the idea of living by myself in some other corner of the desert was not appealing. No. My place was at the University. So long as I had the privilege of escaping to the Bryants when the need arrived, I could seek solace in my work. And at that thought I felt a surge of joy; after only two days here, I was beginning to think hopefully of my work again!

Time flowed easily by. We celebrated the advent of 1999 with a little party at which I got mildly drunk. My tensions eased. A burst of summer warmth hit the desert during the first week in January, and we stretched naked in the sun, mindlessly happy. A winter-flowering cactus in their garden produced a cascade of yellow blooms, and bees appeared from somewhere. I let a great furry bumblebee with thighs swollen with pollen alight on my arm, and twitching only slightly, made no effort to shoo him. After a moment he flew to Shirley and explored the warm valley between her breasts; then he vanished. We laughed. Who could fear such a fat bumblebee?

Almost ten years had gone by, now, since Jack had resigned from the University and taken Shirley into the desert. The turning of the year brought the usual reflections on the passage of time, and we had to admit that we had changed very little. It seemed as if a kind of stasis had settled over us all in the late 1980’s. Though I was past 50, I had the appearance and health of a much younger man, and my hair was still black, my face unlined. For that I gave thanks, but I had paid a steep price for my preservation: I was no further along in my work this first week of 1999 than I had been the first week of 1989. I still sought ways of confirming my theory that the flow of time is two-directional and that at least on the subatomic level it can be reversed. For a full decade I had moved in roundabout ways, getting nowhere, while my fame grew willy-nilly and my name was often mentioned for the Nobel. Take it as Garfield’s Law that when a theoretical physicist becomes a public figure, something has gone awry with his career. To journalists I was a glamorous wizard who would someday give the world a time machine; to myself I was a futile failure trapped in a maze of detours.

The ten years had flecked the edges of Jack’s temples with gray, but otherwise time’s metamorphosis had been a positive one for him. He was more muscular, a brawny man who had utterly shed that indoor pallor; his body rippled with strength and he moved with an easy grace that belied his vanished awkwardness. Exposure to the sun had darkened his skin for good. He seemed confident, potent, assured, where once he had been wary and tentative.

Shirley had gained most of all. The changes in her were slight but all to the good. I remembered her as lean, coltish, too ready to giggle, too slender in the thigh for the fullness of her breasts. The years had adjusted those minor flaws. Her golden-tan body was magnificent in its proportions now, and that made her seem all the less naked when she was nude, for she was like some Aphrodite of Phidias walking about under the Arizona sun. Ten pounds heavier than in the California days, yes, but every ounce of it placed perfectly. She was flawless, and, like Jack, she had that deep reservoir of strength, that total self-assurance, which guided her every move and every word. Her beauty was still ripening. In two or three more years she would be blinding to behold. I did not wish to think about her as she one day would be, withered and shrunken. It was hard to imagine that these two — and especially she — were condemned to the same harsh sentence under which we all must live.

To be with them was joy. I felt whole enough, in the second week of my visit, to discuss the problems of my work with Jack in some detail. He listened sympathetically, following with an effort, and seemed not to understand much. Was it true? Could a mind as fine as his have lost contact so thoroughly with physics? At any rate he listened to me, and it did me good. I was groping in darkness; I felt as though I was more distant from my goal now than I had been five or eight years before. I needed a listener, and I found him in Jack.

The difficulty lay in the annihilation of antimatter. Move an electron back in time and its charge changes; it becomes a positron and immediately seeks its antiparticle. To find is to perish. A billionth of a second and the tiny explosion comes, and a photon is released. We could sustain our time-reversal thrust only by sending our particle back into a matter-free universe.

Even if we could find enough power to hurl larger particles — protons and neutrons and even alphas — backward in time, we would still enter the same trap. Whatever we sent to the past would be annihilated so swiftly that it would be the merest microevent on our tracking scanner. The newstapes to the contrary, there was no chance at all of true time travel; a man sent back in time would be a superbomb, assuming that a living thing could survive the transition into antimatter in the first place. Since this part of our theory seemed incontestable, we had been exploring the notion of a matter-free universe, seeking some pocket of nothingness into which we could thrust our backward-going traveler, containing it while we monitored it. But here we were beyond our depth.

Jack said, “You want to open up a synthetic universe?”

“Essentially.”

“Can you do it?”

“In theory we can. On paper. We set up a strain pattern that breaches the wall of the continuum. Then we thrust our backward-moving electron through the breach.”

“But how can you monitor it?”

“We can’t,” I said. “That’s where we’re stuck.”

“Of course,” Jack murmured. “Once you introduce anything but the electron into the universe, it’s no longer matter-free, and you get the annihilation that you don’t want. But then you’ve got no way of observing your own experiment.”

“Call it Garfield’s Uncertainty Principle,” I said faintly. “The act of observing the experiment queers it instantaneously. Do you see why we’re hung up?”

“Have you made any efforts at opening this adjoining universe of yours?”

“Not yet. We don’t want to go to the expense until we’re sure we can do something with it. For that matter, we’ve got a little further checking to do before we dare try it. You don’t go about ripping space-time open until you’ve run a mock-up of every possible consequence.”

He came over to me and punched me lightly in the shoulder. “Leo, Leo, Leo, don’t you ever wish you had decided to become a barber instead?”

“No. But there are times I wish physics were a little easier.”