“Sure, that’d be fine. Thanks.” She slipped quietly out the door.

Under the black cloth, a small loaf of bread and a wedge of crumbly cheese, like an old cheddar. A plate of dried apple slices on a string. Raisins in a cup, plumped with sweet wine. Ceramic flasks of water and red wine. It wasn’t Twinkies and speed, but it would do.

In fact, he had become ravenous, and though it was fine, he could have eaten twice as much. He kept the water and wine bottles and the ceramic cup that matched them, and set the rest on the floor in the hall.

There wasn’t much else in the room. A filing cabinet that was empty except for the bottom drawer, which held a rolled-up black leather bag. He’d seen people carrying them in the corridor; it was evidently a standard item. He’d use it to move his stuff here from the rented room; less conspicuous than the taxi driver’s plastic shoulder bag.

He sat down and practiced writing with the pen for a while. One of the nibs was flexible, and his writing with it went all over the place. The blunt one Martha had used worked best.

It wouldn’t be too smart to put his speculations down, where they could be read by others. He wrote random stuff for about a half hour and then his hand began to stiffen up. He dutifully made sure all the nibs were clean, waiting for their potato, and went downstairs to have a walk and look around.

The quadrangle that used to front the Green Building was still there, sporting oversized rusted bolts that had once held down the Brancusi Flying Wing. Too secular, he supposed, or maybe it had just worn down.

The silence of the place was eerie. It had always been relatively quiet, shielded from the Mem Drive traffic noise, but when the weather was as nice as this, there ought to be lots of students playing pickup football or Frisbee circles. Not a soul in sight now.

But then a bell chimed for end of classes, evidently, and there were dozens, then hundreds, of students surging out into the sunshine. They were very quiet, but then back in his day they hadn’t exactly been a horde of rabble.

He walked along with them, trying to blend in, but he did notice an occasional furtive glance. Maybe his evident seniority and lack of scars.

They walked among the low wooden buildings, a combination of dorms and meeting halls, to a large central building that smelled of cooking. Matt turned around and passed back through the crowd, observing.

In his time, about half the students would have been Asian. In this crowd there wasn’t a single one, and few black people. Was that the result of gradual change, or had there been a sudden purge? If he could find a reliable history of MIT, he could infer a lot about the missing history of the world. Even an unreliable history would hint at things.

He saw the back of a large sign a block away and angled toward it. It was at the easternmost entrance to the old campus, and it used to be a welcome sign with a map.

It still was, though the disciplines invoked were different. Anointed Preaching, Satanic Nature, Blood Covenant. What was a blood covenant and how many courses could they offer in it? Finally he found Natural Philosophy and Metaphysics, a part of the Mechanical and Mathematical Studies wing in Building 7, not far from his office. It might be a good idea to visit it now, incognito.

The walls on the Green Building had been a kind of inspiration, displays about the history of science, mostly physics, with replicas of old experiments along with old photographs. The walls in Building 7 were inspirational, too: reproductions of dignified paintings of Jesus and various saints. No cluttered bulletin boards, no stacks of returned papers—certainly no cartoons or provocative articles taped to doors, which used to be a professor’s declaration of individuality.

Perhaps Theosophy didn’t encourage individuality. He thought of Father Hogarty’s impatience with Martha.

He went into an empty classroom—none of them were in use at this hour—and sat down in the chair behind the teacher’s desk, fighting a tide of helplessness and panic. He was nottrapped here. He knew that ultimately he would find his way back, at least to the offices of Langham, Langham, and Cruise, in 2058.

He might have to go farther into the future, though, before finding that kind of rabbit hole. Maybe he should push the button now, before he got into trouble with these religious nuts. But there was no guarantee that the world 2094 years in the future would be safer or more sensible.

This place should have been comfortably familiar. He had spent most of his life in classrooms, and for many of his years had aspired to be right here, in front of a room full of young people pursuing knowledge. It smelled right; it felt almost right. But on the wall behind him there should be a clock. Not a picture of Jesus smiling benevolently.

Well, he’d spent many an hour staring at those clocks, praying for time to pass more quickly. Maybe kids were just more literal about that now.

He checked his watch. There wasn’t quite enough time to walk up to Magazine Street and back, but maybe he didn’t have to walk. He’d seen horses with carts parked across the street from Building 1, where there used to be a cab stand.

He went up to the office and retrieved the black bag, then went down and engaged the lead cart of four waiting there. The driver wanted eight dollars each way, but allowed himself to be bargained down to thirteen for a round trip.

It was stifling hot in the sun, but the cab had a leather canopy and moved just fast enough to generate a cooling breeze. It made the trip in a leisurely ten minutes, about what it would have taken in Matt’s time, crawling through traffic and waiting for lights.

The landlady wasn’t there. Nothing seemed to have been disturbed in the strongbox, so he transferred his stuff to the black bag and was back in his office by 2:30.

Waiting for Martha, he leafed through Metaphysics and the Natural World, which was full of biblical citations, but in between them did do a fair job of outlining Newtonian mechanics and basic electricity and magnetism, presupposing a knowledge of elementary calculus and trigonometry. The section on what caused the sun and stars to shine was ingenious, the heat generated by gravitational compressionand the constant infall of meteorites. It allowed for the Sun to be about six thousand years old, and close to burning out, which of course would happen on Judgment Day.

Martha knocked on the door just as bells were chiming for change of classes. “Shall we go find your quarters, Professor? ”

“Sure.” He got up and shouldered the bag.

She held out her hand. “Let me take that for you.”

“No, that’s all right.” The revolver’s heft was pretty obvious.

“But I’m your graduate assistant.” It was almost a whine.

“Look, Martha. I was a graduate assistant myself not so—”

“What? Menwere graduate assistants back then?”

“Sure. About half and half.”

She shook her head, openmouthed. “But what . . . what did you do?”

“Helped my professor out. Mostly math and electronics—that’s working with electrical machines. I gave tests and graded papers.”

“I can’t do anything like that,” she said. “I’m not supposed to. That’s for scholars.”

“So what does a graduate assistant do here?”

“I’m a graduate,” she explained. “And I’m your assistant. ”

“Oh. Okay. But humor me on this: I carry the bag.”

She shook her head. “But you’d look like a scholar, not a professor.”

“Humor me, Martha.”

Her mouth went into a tight line. “If Father Hogarty sees us, will you tell him it was your idea?”

“Absolutely.”

He followed her down the stairs and across the quadrangle, the same route he’d taken after lunch, but they kept going on past the dining hall. It was obvious when they entered professors’ territory: the residences were smaller, individual cottages, and instead of browning lawns they were fronted with carefully raked gravel and luxurious potted plants.