I took a deep breath, ready to attempt a very drastic and risky ident.i.ty switch. "We'll take this slow. I don't want you to have a heart attack. First of all, I live in Manhattan."

"Okay."

"Do you want to come to my place? I'll tell you the rest there."

He nodded, slowly. "Just so you know ... I've got friends who know exactly where I am, in case I don't show up later."

I rolled my eyes. "Sure you do."

Adam looked up at the building with wide eyes. "You live here?"

"Yup."

We took the elevator up. During our ascent, Adam was twisting his hands and darting his eyes around like the Hacker Police were going to jump out at him any second.

"Who's your friend?" Dad asked when we walked past him in the front room.

"This is Adam Silverman. Adam, this is my dad."

Adam shook his hand. "Nice to meet you, sir."

"Jackson, I'm going out of town for a couple days."

"For what?"

"Business in South Korea. I left you a message earlier, but you didn't return my call. Someone's picking me up in five minutes. Will you be okay?"

"Since when do you have business in South Korea?"

His eyebrows lifted as if to say he wasn't going to talk about this with a stranger present.

"See you in a few days." I walked down the hall with Adam trailing behind me. I led him to my room and shut the door before pointing to the couch on the far side of the room. He walked over and sat down, watching closely as I pulled a silver lockbox from my desk drawer. After sifting through a stack of pictures, I handed him a few. I had just made prints from my 2009 memory card yesterday, thinking they might seem more real like this.

"Is this-"

"Holly," I finished.

He flipped it over and looked at the back, then a huge grin spread across his face. "Nice. This is really elaborate. And it's kinda genius how you tie in my science project. Most people know about the theory of relativity part, but actually taking the next step and throwing time travel at me ... very creative."

"So ... you don't believe your own research?" I knew a few pictures wouldn't be enough.

"Of course I do, in theory. How did you get these pictures of me? My parents' computer, maybe?"

"I took them myself. And what do you mean, 'in theory'? Either you believe it or you don't."

"I believe time travel is possible, but with a lot more research and probably technology that doesn't exist yet."

"You're wrong," I stated flatly.

"It's not possible?"

"It's very possible and I can do it."

He laughed and shook his head. "All right, prove it."

"What can I say that won't make me sound like a carnival fortune-teller? It's the future. You get into MIT and get a 2300 on your SATs."

"Not a bad score. What else you got?" He leaned back and put his hands behind his head.

I flopped back onto my bed and yanked the journal from my bag before thumbing through the pages. "It's possible I forgot what you told me to say."

"Must not have been important."

"It's not like I really thought I'd get stuck in the past." I sat up and grinned before pointing at his chest. "Your dog just died, didn't he? Like a few days ago?"

"Thanks for the reminder," he grumbled. "But that doesn't prove anything. Jana and I were talking about it tonight. You must have overheard."

"Sorry."

"How did you meet me, in the future?"

"We worked at a day camp together. Holly did, too." I watched his face carefully for any indication he believed me, but it was all calm and cool.

"But you must have proved that you could time-travel at some point, right?"

I nodded. "Yeah, it started something like this conversation. Only we were supervising an all-night campout. The kids were asleep and it was just us. You came up with an experiment and made me jump back and forward again." I opened my wallet and handed him the memory card. "This has lots of experiment data on it."

He flipped it between his fingers while I went back to the journal, trying to find the page with my description of that first experiment.

"That was all it took to fool me? My older self must be an idiot."

"No, you made me do it ten times." The scribbled cursive at the bottom of the April 11, 2009, entry caught my eye. "Here, check this out! You wrote yourself a note."

He s.n.a.t.c.hed the notebook from my hand. I watched as all the color drained from his face and he sank back onto the couch. "How did you get this?"

"You wrote it. I don't even know what it says. Is it Latin?"

"Yeah ... Latin." His fingers froze on the corner of the page.

"What's it say?"

After a long silence, he jumped into action, flipping frantically through the pages, then finally said, without looking up, "Not important. Forget about it."

I stared at the ceiling, waiting patiently for the questions that would inevitably follow. Of course Adam would know exactly what to tell himself. Something he would never doubt. I shouldn't have doubted him, either.

"Jackson, wake up!" Adam stood over me, shaking my shoulders.

It was so bright that I could barely open my eyes. He must have turned on every light in the bedroom. "What time is it?"

"Four."

With all my excursions into different years, saying it was four meant nothing to me. I walked to the window and saw that it was still dark outside. That's when I took in the ma.s.s of computer parts piled on the floor. Extraneous pieces were strewn all over the room and two monitors now sat on the desk.

"What the h.e.l.l-"

"Sorry, I borrowed two other computers from around the house to collate your most recent data. The hard drive wasn't big enough and didn't work with the memory card you gave me, so I kinda ... made my own computer." He shuffled around, picking up loose items and tossing them into the pile faster than I'd ever seen him move.

I studied his current state closely. His black hair stuck up in every direction, pupils dilated like a crack addict, and he was doing the snapping thing with his fingers. I had seen him like this once before after a six-pack of Red Bull. He could probably be declared insane in this state. "Did you have caffeine?"

He held up a thick stack of papers. "I've got some notes to go over with you."

"Let's eat first. Was it Red Bull or coffee?" I shoved him toward the door from behind. He didn't object, but he held the papers to his chest, probably so I couldn't take them.

"Ready for number one on my list of questions?" he asked, plopping down at the kitchen table.

I grabbed some turkey slices from the fridge and a loaf of bread and tossed them onto the table. "All right, but eat while you talk. Soak up some of that caffeine."

He stuffed a piece of bread in his mouth and chewed quickly. "Wait ... so, in 2009 you're nineteen and Holly's nineteen and you're both freshmen at NYU?"

"No, I'm a soph.o.m.ore ... Holly's a freshman."

"Holly's a junior," he said, then immediately shook his head. "This Holly is a junior and the other one is in college ... got it. How did you meet us in March 2009? We were still in high school, right? Or do we graduate early?!"

"No, you don't graduate early.... We started camp counselor training in March ... it was just a few sessions until the summer officially started."

"Dude ... that's a little taboo, isn't it? College guy, hooking up with a high school chick? Oh wait ... guess that's what you're trying to do now ... but worse."

I sighed, fighting the urge to crawl back in bed again. This all made sense in my head. "It's not taboo. That Holly is only four months younger than me. She's one of the older ones in her grade and I'm one of the younger ones.... That's all. Is this really important? And shouldn't you know this already? You've known Holly for how long?"

"Two years ... and my brain is moving too fast to hold on to these minor details. Plus, she was born in '90 and I'm '91 ... and it's throwing me off. Okay, so you commute from here to NYU? And Holly lives in the dorm? Which dorm? Maybe we should go scope it out?"

"You're making me really tired," I said. "I didn't commute from here. I lived in a dorm both freshman and soph.o.m.ore year ... a different dorm than Holly. But you've been here, to this apartment, before ... the older you.... I lived at home during the summer and on breaks. Holly's been here, too ... and to my dorm. Anything else? Need to know all of my professors' names or the path I took to cla.s.s every day?"

Adam paused for a long moment, staring at the paper in front of him, then finally said, "Nope ... not now anyway."

"Next question?" I prompted, rubbing my temples.

"So, what happens if you ... for example ... jump back thirty minutes, then stay thirty-one minutes? Then, technically, you'd be in-"

"The future," I finished. "I've never traveled outside the span of my own life."

He nodded. "That's what I figured. Do you even have to jump back? If you end up staying in the past until it's the same time you left?"

It was so weird being the one explaining s.h.i.t to Adam. "Sorry, I have a few missing pages, but we did that experiment really early on. I just bounce back. Remember, it's different when I'm in the middle of a jump. I feel like I'm not all the way there, like I feel lighter, very little sensation as far as hot and cold. And nothing I do during my normal jumps affects my home base."

"Right," he said, stuffing more bread in his mouth. "All those regular jumps are like some kind of shadow timeline. Or a ... mirror timeline."

"Yeah, like watching the same movie over and over, hoping eventually that the character you don't want to die will somehow make it. Or maybe if you shout a warning at them, it'll change something, but it never does," I concluded. "But how the h.e.l.l did I end up here, in 2007? Not as a ... shadow, but the real me?"

"And how did the other you just disappear?" Adam asked, shaking his head. Then he stared at me with his crazy, caffeine-addict eyes. "I do have a theory."

I rested my elbows on the table, trying to focus, even though it would probably be over my head. "Okay, let's hear it."

"Well, first of all, it's obvious that there's only one version of you in any given home base."

"Yep, but technically, I'm in the past right now."

He leaned forward, over his papers, and slammed his fist on the table. "What if this is another universe!"

I nearly fell out of my chair. "Okay, you are definitely insane."

He scoffed at me and shook his head. "Seriously? All the crazy s.h.i.t that's happened to you and you think I'm insane because I mention parallel universe theory?"

I laughed without even thinking about it. He was right. What the h.e.l.l did I know? "Let's tuck that one away for future a.n.a.lysis. What's the next question on your list?"

"There's a couple times you noted that it felt like you were being forced back. I'll figure out a formula for this, but it seems you can't actually live in the past."

I let out a breath. "Apparently I can ... if I move my home base."

"Exactly. If only we knew how you did that. But I don't get why you can't go back to 2009. Or to that other universe, if we're going with that theory. None of the experiments indicated even the slightest possibility of getting stuck in the past. Although, obviously, I planned for it just in case. By writing the note. My older self, anyway."

I sat across from him and covered his papers with my hand. "So you really do believe me? That I'm from the future?"

I needed to make sure it wasn't just the caffeine talking and that he'd go back to logical, realistic thinking in a couple hours.

"Yeah, there's no doubt in my mind. But did you leave 2009 because you thought those dudes with guns would kill you?"

"You read that part of the journal?" He nodded and I took a deep breath before spilling something I hadn't told anyone, future or past. "Honestly, I don't even remember deciding to leave, but I know staying would have been too hard ... You read about my sister, right?"

"Cancer, brain tumors, died in April of 2005," he rattled off from his notes.

"I wasn't there when she died," I admitted.

Adam lifted his eyes to mine, staring intensely. "I thought the time-traveling didn't start until years after that."

"I mean, I just wasn't there. Like, in the room with her." I swallowed the lump threatening to form in my throat. "You know how people always say they wished they could have been there, to say good-bye or whatever?"

He pushed the notes aside and rested his arms on the table. "Yeah?"

"Well, I didn't want to be there. I was too scared. Not so much about talking to her, or being sad, but the actual act of watching someone go from living to ... not living. I saw it in my head so many times, her chest moving, taking in deep breaths, and suddenly it just..."

"Stops," Adam finished for me.

"And then I was thinking all these things, like ... when does she stop hearing us? Is it after her last breath? Because people hold their breath all the time, maybe she would still hear us or be processing thoughts." I rubbed my eyes, ridding them of the blurriness. "It's stupid ... I know."