Matt reached into his pocket and took out something she immediately recognized as one of the marbles he had tinkered with five years earlier, when he was trying to duplicate the time machine. It looked like ordinary red glass, in a square cage with ridges that could be interlocked with other cages to slide over each other in any direction.

He held it between thumb and forefinger and started twisting it in the air. Left, right, right some more, forward, left again... she soon lost track of the permutations. It was like watching a safecracker twisting the dial, only he turned it through three axes. Then he stopped. Nothing happened.

"Nice trick," she said.

"It doesn't work every time. That's what's so frustrating. In science as I knew it, repeatability is everything. With this stuff... well, like my grandfather used to say, 'It don't work unless you hold your mouth right.' " He went through the motions again, and she was amused to see that he actually had screwed up one side of his mouth in an odd way, though she didn't think he was aware that he was doing it. Then he set it down on the table between them... and this time the little wire cube with the clear red glass ball in it seemed to be seized by a mysterious energy. It began to spin.

It... unfolded itself. Watching it, incredulous, Susan thought each move was as logical as unfolding a paper airplane or taking a flattened box and turning it into an assembled one... but neither of those operations hurt her eyes. This was an evolution that she felt instinctively that human eyes were not equipped to witness. Now there was a larger cube, three marbles on a side, now four, now five... and in a few eye-popping seconds there was the whole array, and the box that contained it, laid out like an opened suitcase in front of her.

She got up and hurried to the bathroom.

"FEELING better?" Matt asked when she got back.

"I didn't actually lose the beer," she said. "But for a minute there I felt sick as a dog."

"I told you it was a roller-coaster ride."

"Matt... what did you just do?"

"The only thing I've learned to do. That night, the night that began with the mammoths about to stomp us, and ended up back in Los Angeles... I watched this thing do its stuff. I ended up with that one little glass ball, and then I got hit by a city bus. I knew I had seen something and I thought I could remember it, and I knew I had to get out of there. It wasn't until later that I found the ball in my pocket. I don't remember putting it there. We were sort of busy, if you recall. Later, I figured out that the ball was still somehow attached to the rest of the machine. I did computer simulations on the model I had stored in my computer, and eventually came up with an algorithm that... that sort of pries up the lid on the place where the rest of the machine is."

"So you've had it all the time."

"That's right. All through the interrogation. But I didn't know what to do with it. I still don't."

"Why not just give it to Howard?"

Matt sighed. "I would love to do that. I don't want this thing. It's like... it's like you own a gun and you know how to fire it, but you haven't figured out how to aim it yet, and it can shoot in any direction, totally at random. How often are you going to shoot that gun? It's even worse, though, because sometimes it just goes off by itself, when it wants to, when the conditions are right, when God or Coyote wills it... I don't know."

"All the more reason to get rid of it. Give it to Howard." "Susan, Howard is a collector. That's what he wanted a time machine for in the first place. He wanted me to get him a mammoth, or the means to get one. We did, accidentally. He was fixated on mammoths at the time... but you think he'd be satisfied with that? Why not dinosaurs? He could build a real Jurassic Park."

"Believe me, if I thought it was that simple I'd go back with a big-game trapper and bring some more mammoths forward in time. But..."

"But what?"

"But I think it might be very dangerous."

Susan chewed it over for a time.

"You're talking about changing the past, right?"

"Yes. I don't know if it's possible. Maybe we could change the past and make a better world. Maybe we could make a worse one. Or maybe the way things have happened, are happening, and will happen is written in stone, and can't be changed. I lean toward that last possibility."

"Predestination."

"If you want to call it that. It could be that free choice is illusion. I don't think I have the right to test it."

"I see what you mean. But there's one question I've been meaning to ask you, ever since, ever

since you made that... that thing appear. Who made it?"

"I made it."

"No, no, I know you made that one. Who made the original one?"

"There is only one. I made it. You watched me."

"But that's... that's crazy! The only way you knew how to make it was you took it apart and

found out how to make it."

"Yeah. It's a puzzler, isn't it? Time travel is full of stuff like that."

"But... where did it come from? Why is it here? What's the point of it?"

Matt smiled.

"That's the big question, isn't it? Why? All my life I've been much more concerned with what and how. Science in the main doesn't attempt to tackle the meaning of things. I hardly even know how to phrase the questions I need to ask. I'm still learning my ABCs, and I've got a sneaking feeling that nobody, nobody has even gotten as far as Z yet, much less learned to read. That's been a comfort to me, trying to understand this, that just about everyone else is almost as ignorant as me.

"The right thoughts? You mean..."

"I think it was my mind that sent us back, and brought us home. But it doesn't work all the time. You have to be in the right place, too. We appear to be on an unscheduled loop on the roller coaster of time.

"But one of the few things I know for sure is... that if that loop hadn't happened, we never would have met. That's the most important thing in the world to me."

Susan wondered if she was going to cry. She held it in, because there were still more questions she had to ask. She was starting to be disturbed.

"What else are you sure of? You said you had a trick, which you showed me, and that's good enough, please don't turn it on. And you made a discovery. And... I thought the roller-coaster ride through time was over."

Matt looked down at the table, then met Susan's eyes again.

"Not quite. To make the discovery, I had to go back to the beginning. I had to go to northern Canada, to Nunavut."

30

THE place was called Kangiqiniq, formerly Rankin Inlet, and it was located about three-quarters of the way up the western shore of Hudson Bay, which put it in the balmy, sun-kissed southern regions of Nunavut.

Matt had never felt so cold.

It began as soon as he stepped off the small plane from Winnipeg, which had been cold enough. It got worse as he moved around the streets of town. Kangiqiniq was a bustling metropolis, for Nunavut. Population almost five thousand, very few of whom seemed to spend any time on the streets. It made sense. The wind howled down the arrow-straight streets between the mostly modular buildings, direct from the North Pole—which was actually the northernmost point in the territory.

There were a lot of parked snowmobiles. Most of the town was not fancy, but in addition to traditional native ways of making a living there was a thriving tourist industry catering to hunters, fishermen, and eco-touring. People who could afford to indulge in things like that usually didn't like to stay in tarpaper shacks, so there were half a dozen fancy resorts built from imported stone and timber, pretending to be Swiss ski lodges or Colorado vacation mansions. They all had indoor pools and gyms, plush rooms, good restaurants. There was actually a golf course, possibly the northernmost one in the world.