As soon as he heard that neither Paul nor his attendant was nearby, a change seemed to come over Dr. Slaski. He straightened up in his chair, lifting his head so he could fix me with a rheumy-eyed stare. The drooling stopped right away.

"Oh," he said when he saw it was me. He didn't exactly look thrilled. "You again."

I didn't think that was completely fair, seeing as how the last time the two of us had spoken, he had sought me out . . . sought me out to deliver a cryptic warning about his own grandson, whom he'd equated to the devil, no less.

But I decided to let that slide.

"Yes, it's me, Dr. Slaski," I said. "Suze. Listen. About Paul."

"What's that little pisser been up to now?"

Clearly there is very little love lost between Dr. Slaski and his grandson.

"Nothing," I said. "Yet. At least, so far as I can tell. It's what he says he can do."

"What's that, then?" Dr. Slaski asked. "And this better be good. Family Feud comes on in five minutes."

Good God. Was I, I wondered, going to end up wheelchair bound and addicted to game shows when I was Dr. Slaski's age? Because Dr. Slaski - or Mr. Slater, as Paul wanted everyone to think of him - is also a mediator, one who'd gone to the ends of the earth looking to find answers about his unusual talent. Apparently, he'd found what he was looking for in the tombs of ancient Egypt.

Problem is, nobody believed him. Not about the existence of a race of people whose sole duty it was to guide the spirits of the dead to their ultimate destinations, and certainly not that he, Dr. Slaski, was one of them. The old man's many writings on the subject, most of them self-published, went ignored by the scientific and academic communities, and were now gathering dust in plastic bins beneath his grandson's bed.

Worse, Dr. Slaski's own family seem to be trying to sweep him under the bed, as well, Paul's father even having gone so far as to change his name to avoid being associated with the old man.

And what had Dr. Slaski gotten for all his efforts? A terminal illness and his grandson, Paul, for company. The illness, or so Dr. Slaski claimed, had been brought on by spending too much time in the "shadowland" - that way station between this world and the next. And Paul?

Well, he had brought Paul on all by himself.

I guess he had a reason to feel bitterly toward the human race. But why he felt that way toward Paul, I was only just learning.

I tried to start out slowly, so he'd be sure to understand.

"Paul says mediators - "

"Shifters." Dr. Slaski insisted people like him and Paul and me are more properly called shifters, for our (in my case, newly discovered) ability to shift between the dimensions of the living and the dead. "Shifters, girl, I told you before. Don't make me say it again."

"Shifters," I corrected myself. "Paul says that shifters have the ability to time travel."

"Indeed," Dr. Slaski said. "What of it?"

I gaped at him. I couldn't help it. If he'd hit me in the back of the head with a pinata stick, I could not have been more surprised. "You . . . you knew about this?"

"Of course I know about it," Dr. Slaski said acidly. "Who do you think wrote the paper that gave that fool grandson of mine the idea?"

This is what I got for not paying more attention during my mediator sessions with Paul.

"But why didn't you tell me?"

Dr. Slaski looked at me very sarcastically. "You didn't ask," he said.

I sat there like a lump staring at him. I couldn't believe it. All this time . . . all this time I'd had another skill I'd known nothing about. But what would I have ever needed the ability to time travel for, anyway? I guess there were a few bad hair days I wouldn't have minded going back and fixing, but other than that. . . .

Then, like a bolt of lightning, it hit me.

My dad. I could go back through time and save my dad.

No. No, it didn't work that way. It couldn't. Because if it could . . . if it could. . . .

Then everything would be different.

Everything.

Dr. Slaski coughed, hard. I shook myself and touched his shoulder.

"Dr. Slaski? Are you all right?"

"What do you think?" Dr. Slaski demanded, not very graciously. "I've got six months to live. Maybe less, if those damned doctors have their way and keep bleeding the life out of me. You think I'm all right?"

"I . . ." It was selfish of me, I knew, but I didn't have time to listen to his health problems. I needed to know more about this new power he - and possibly I - had.

"How?" I demanded eagerly. "How do you do it? Travel through time, I mean."

Dr. Slaski glanced at the TV. Fortunately the credits for The Price Is Right were still rolling. Family Feud hadn't started yet.

"It's easy," he said. "If my idiot grandson can figure it out, any moron can."

We didn't have much time. Family Feud was going to start at any second.

"How?" I asked him again. "How?"

"You need something," the doctor said with exaggerated patience, like he was talking to a five-year-old. "Something of the time you want to go to. To anchor you to it."

I thought of a time-travel movie I had seen. "Like a coin?" I asked.

"A coin would do it," Dr. Slaski said, though he looked skeptical. "Of course, you'd need to use a coin that had once been owned by a specific person who existed in the time you want to go to, and who'd once actually stood where you're standing. And you need to pick a spot you can get back to without shifting onto some innocent bystander."

"You mean - " I blinked. "You mean when you go back, all of you goes back? Not just - "

"Your soul?" Dr. Slaski snorted. "Lot of good that what do, wandering around in some other century without any body. No, when you go, you go. That's why you've got to be smart about it. You can't just go hopping through time and space all willy-nilly, you know. Not if you want to keep your guts from spilling out. You've got to go to a spot where you knew the person once stood, hold the object they once owned, and - "

"And?" I asked breathlessly.

"Close your eyes and shift." Dr. Slaski looked back at the television, bored by the whole conversation.

"And that's it?" It was easy. "You mean I can just pop back through time and visit anyone I want?"

"Of course not," Dr. Slaski said, his gaze glued to the TV screen. It was almost as an afterthought that he added, "He's got to be dead, of course. And someone you've mediated. I never determined why, but it must have something to do with that person's energy, or being. Must be the link . . ." Dr. Slaski trailed off, lost in research done decades before.

"You mean . . ." I blinked in confusion. "We can only go back through time if it's to help a ghost?"

"Give the girl a prize," Dr. Slaski drawled, turning his gaze back toward the television.

For once I didn't mind his sarcasm. Because ghosts? Ghosts I can deal with. Ghosts like . . .

. . . well, my dad, for instance.

And I had plenty of stuff that once belonged to Dad. I still had the shirt he'd been wearing the day he died. I had plucked it from the pile of things the hospital had given us and kept it under my pillow for months after he'd died . . . right up until the day I finally saw him again, when he appeared to me, and told me exactly why it was that I, but not Mom, could see him.

I thought my mom hadn't known about it - the shirt, I mean - but now I knew she must have. She surely would have found it when she was making my bed or playing tooth fairy.

But she had never said anything. To be fair, she couldn't say anything, because she kept Dad's ashes in his favorite beer stein for years before we finally got the guts to scatter them in the park where he'd died, the park he'd loved so much, just before her wedding to Andy.

A park, I realized, I'd have to go to if I wanted to go back through time to save him, because the apartment we'd lived in had been sold and I couldn't very well walk up to the new owners and be all "Can I stand in your living room for a minute? I just need to pop back through time to save my dad's life."

Of course, both the park and the apartment were all the way across the country. But I had some babysitting money saved up. Maybe even enough for a plane ticket. . . .

I could do it. I could totally keep my dad from dying.

"What else?" I asked Dr. Slaski, with a glance at the TV. A commercial, thank God. "When you have the . . . thing that belonged to the ghost, and you're standing in a spot where he once stood? What do you do then?"

Dr. Slaski looked annoyed. "You hold the object - that's your anchor - and nothing else. That's important, you know. You can't be touching anything else or you could end up taking it with you. Then you picture the person. And then you go. Easy as pie." Dr. Slaski nodded at the TV. "Turn it up. Feud'll be on in a minute."

I couldn't believe it was so easy. Just like that, I could go back through time and keep someone I loved from dying.

"Of course," Dr. Slaski said casually, "once you get there - to where you're going - you have to watch yourself. You don't want to be changing history . . . at least, not too much. You have to weigh the consequences of your actions very carefully."

I didn't say anything. What possible consequences could my saving my dad have? Except that my mom, instead of crying into her pillow every night for years after he died - right up until she met Andy, actually - would be happy? That I would be happy?

Then it hit me. Andy. If my dad had lived, my mother would never have met Andy. Or rather, she might have met him, but she would never have married him.