Me.

It has to be easy, like . . . a letter-number cipher? The simplest cipher there is a.s.signs a number to each letter of the alphabet. A is 1, B is 2, C is 3, and so on. I rush through the alphabet in my mind, counting on my fingers. Sandline translates to 19-1-14-4-12-9-14-5. Is that it?

I type in 191144129145. The light stays red.

No, maybe it's a standard eight-digit code. I have to break it down further so each letter has only one digit. S is 19. Add the 1 and 9 together and get 10. Add the 1 and the 0 together and I come up with 1.

S is 1.

A is 1.

1-1.

N is 14, which is 5. I go through the rest of the word, and then I have it.

1-1-5-4-3-9-5-5.

I cross my fingers with my left hand and type it into the keypad with my right. And then the light turns green.

The safe holds all sorts of goodies. I go straight for my watch. I enter the same code, and the robotic voice of the briefcase echoes throughout the room as the case clicks open. I mutter a "Hush!"

After the watch is around my neck, I go for the money box. It's all organized by decade. I have no idea what to take, so I just start opening the drawers and shoving fistfuls of cash into the duffel bag. Then I run down the hallway and step into the gravity chamber.

I have to go to Peel. To the day Alpha died. I know what Red said; I know about the dangers of running into myself. But that's the only date when I know I had Alpha's notebook on me, and that notebook is the only way I'll be able to find out the XP missions.

And so I shut the watch. Time to rendezvous with myself.

CHAPTER 21.

It's a February morning when I land, and I instantly realize I didn't pack a coat. I'm wearing the old, olive-green hoodie and yoga pants I wore to Mike's, but that's not exactly winter weather gear. I have a coat hanging upstairs in my closet. A warm, puffy down one. But I was a wanted woman in February. I need to get out of Annum Hall. Now. So I open a door in the gravity chamber, the one that leads outside. An icy wind blows right through my hoodie, penetrating my skin.

I hunch my shoulders and tear across the Common to the Park Street T stop. I buy a new Charlie card, and soon I'm huddled inside the bus depot at South Station, my teeth chattering. An old woman sits on the bench across from mine. She looks at my hoodie, then frowns and hugs her oversized purse and bag of groceries closer, as if any second now I'll leap over the aisle at her. Do I really give off such a crazy vibe? Maybe I am my mother's daughter.

I'm grateful for the warmth on the bus. I sit next to a window and put my hands against the slatted heater. The metal burns, but I don't move my hands. It's a good pain.

A half hour later, the bus dumps me a short distance from Peel. I take the shortcut through the woods, then squeeze myself through the hole in the fence.

And I'm on campus. In just a few minutes, Alpha is going to be here. Then most of my team is going to project here from 1982, from when they found Yellow and me. Yellow will have been shot. Later, Abe and I will arrive. Then there will be helicopters and a SWAT team, and Alpha and I will go running across campus and into the science building. Where Alpha will die and I will cause an explosion.

I stare at the science building. At its plain brick exterior. It has none of the charm of the old New England prep schools. There are no notches in the bricks; there is no arched wooden door, no wall of ivy snaking up the side. No, this building is like every other building on Peel's campus. A big rectangle. Tilt walls hoisted up with a brick facade slapped on top. Efficiency and cost savings; that should be Peel's real motto.

In less than an hour, that building is going to be on fire.

I need a game plan, but I can't think of where to start. I can't be seen. Certainly not by my Annum Guard teammates, definitely not by myself, and really, not by anyone on campus. Peel doesn't have that many students. We all basically know one another. And that long-lost twin explanation only flies on soap operas.

This is a suicide mission. But before my brain can come up with another thought, there are footsteps pounding right toward me. I look up to see Alpha and Red running in my direction, and I slip back through the bent bars of the fence and flatten myself against the hedge. I drop the duffel bag to the ground. My heart is hammering in my chest.

"They'll be back soon!" Alpha yells. "Capture immediately, and use any force you deem necessary."

Red doesn't say anything. I wonder if he's already suspecting that Alpha isn't being entirely truthful. After all, he's about to save my a.s.s and call in SWAT after he learns the truth about Alpha.

Less than a minute later, there's a series of loud zips, followed by lots of screaming.

"My sister!" Indigo wails. "Help her! Help her!"

My entire body is shaking, and it's not from the cold. I don't even feel that anymore. I slide a branch out of the way and peek my head around. Yellow is on the ground. Indigo and Violet have crouched down next to her. Indigo's hands are covered in blood. Green is holding Blue-Tyler Fertig-with his hands clasped behind his back. Red rushes over to Yellow. He pushes Violet and Indigo out of the way and puts two fingers on her neck.

"Still breathing!" he yells to Alpha.

Alpha doesn't move.

Red keeps one hand on Yellow and puts the other to his ear. He bends his neck into his chest and says something into his earpiece. I take a step forward to try to hear.

A stick cracks and breaks beneath my feet.

Red's head whips up, and I let go of the branch and drop to the ground. No more peeking. I'm trapped here until the old me chases Alpha into the building. Making a move now is too risky.

And so I stay here, crouched on the ground, reliving one of the worst days of my life. An ambulance wails onto campus. More sirens follow. My teammates pile into cars. The tires squish in the mud, leaving a damp smell when they depart.

Now only Alpha and Red remain, and I take a slow breath. I close my eyes. I need to prepare for what's about to happen.

And then there are two pops. Abe and I are back. I hear my own anguished cry when I think Abe's been shot. I have to clasp my hands over my ears, but it doesn't block out the sound.

I'm trembling. A wave of nausea bubbles in my stomach, then rises up into my throat. I thought I was past this day, that I'd come to grips with everything. I haven't.

The old me is shouting at Alpha now, and in the distance, I hear the helicopters. There's another buzz as Alpha Tasers Red, and then I prop myself up and peek through the bushes again.

I watch myself chase after Alpha.

I have to follow.

I push through the bars and pull my hoodie strings tighter. I keep my head down and jog across campus.

"Is that Amanda Obermann?" someone gasps, and I think my heart stops.

But then I glance up to see Jackson Rybaks pointing to the old me who's just sprinted into the science building.

"What's going on?" Ashlee Chroma yells as I brush past her.

I don't look at her. I don't look at anyone. I slip inside the science building and head for the stairs.

"When are you going to give up?" I hear myself shout from the floor above.

I rub my temple and linger in the stairwell. Listening. Waiting.

"Don't do anything stupid," I hear myself say to Alpha.

I close my eyes, and a memory floods the blackness. Right now, Alpha has a gun pointed at my temple.

"I'd give you the same warning," Alpha tells me, "but it seems we're a bit late for that."

And then a door clicks closed.

I sprint down the hall, past the advanced chem lab where I'm locked in with Alpha, and into the biology lab next door. There's yelling in the next room. A scream from me. I think Alpha just held my hand in front of a Bunsen burner. I'm going to throw up. I put both hands on my stomach and bend over. And then the door to the chem lab opens and shuts as Headmaster Vaughn enters, and less than a minute later there's a shot that echoes throughout the entire floor.

Alpha is dead.

Again.

And I do throw up. I retch into a trash can next to the teacher's desk. I shouldn't have thrown in the towel after only one week of the counseling the government arranged for me. I'm not over this.

Shouts come from the hallway. The SWAT team is here. I only have about thirty seconds to make a move, and I'm blowing them!

I remember what they taught me, right here on this campus: how to compartmentalize. I close my eyes and isolate this day. This one day in my history. I allow myself to linger, to revisit, to continue feeling, for just a few more seconds. Then I visualize a filing cabinet. One of the big, gray metal ones. I mentally slide open the top drawer and slip this day inside. Then I shut it.

I open my eyes. We're back in business, and I'm about to cause an explosion next door. I slink to the window and open it, to try to minimize the- BOOM!.

I slam to the floor and put my hands over my head. The walls shake. Several of the stools fly across the room. Microscopes dance on the shelves and crash to the ground. Then there's silence.

I push myself up. The walls are swirling in front of me, and I wobble to the side. But I have to do this.

I climb out the window and swing myself into the one next door. The old me is lying unconscious in the hallway. Abe is beside me, yelling. A SWAT guy kneels down next to me. Headmaster Vaughn is in a crumpled heap by the trash can. And the notebook is smoldering right beside him. The notebook that details every mission Alpha sold and for how much.

I leap into the room, scoop up the notebook, then climb back out the window and into the next room.

"Evacuate the building!" SWAT yells from the hallway.

Not good.

I poke my head out the window. I'm three floors up. I can't project yet because SWAT has to find the notebook. And I can't very well leave it in this room because that would lead to questions no one could answer. I turn my head to the right. There's a drainpipe.

That will have to do. I'm out the window again. I grab onto the pipe. It creaks and snaps and pops away from the wall.

No!

I slide down as fast as I can. The pipe bends. No, no, no! I'm level with the second-floor windows. I peer into a lecture hall. Then the pipe breaks away from the wall. I tuck myself into a ball and crash into the bushes below. I land with a thud and groan. I roll my ankles and wrists a few times. Tenderness but no pain. I don't think anything is broken.

There's shouting from above and screaming echoing across campus. I crouch low in the bushes, open the notebook, and flip through. There's an XP entry a few pages in: XP.

150.00.

A hundred and fifty grand. I memorize the date. There's another one after a few more pages. And then one more. And that's all I see. Three. Only three.

I don't have time to double-check. I ditch the notebook in the bushes, below the chem lab window, and I run off across campus.

No one pays me any attention. Everything is in chaos. Students run screaming to their dorms. Teachers try to usher everyone away from the buildings. I run toward the back corner of campus and squeeze myself through the fence. Then I grab the duffel bag and unzip it. I have to dig for the mission ledger. It's sandwiched behind a wad of cash and a dress that was in style more than a hundred years ago.

I repeat the XP dates out loud, then trace my finger down each of the pages as I look for them. I find all three and put little check marks next to them. And then I close the bag, project to the present-to June-and run toward the bus station.

Everything feels surreal, like I've just woken up and I'm remembering a dream. It's not until I'm on a bus, halfway back to Boston, that I even realize I got on a bus.

We pull into South Station, and I think about hopping in a cab, but instead I opt for the subway. It's more anonymous, and anonymity keeps me safe. I have to catch two trains, but soon I'm climbing the steps at Copley Square. The Boston Public Library is right across the street. I look both ways before I run across Boylston on a "Don't Walk" and in through the front doors.

I head for the computers and put the duffel bag on the empty seat next to me. Breathe. Breathe. I take a minute. Two minutes. I close my eyes and focus on my breath. It's what my training tells me to do. The only way I can think of to ground myself.

When I open my eyes, I feel only marginally better, but I'm not shaking anymore. I grab the mission ledger and find the first check mark. I type "511 Tenth Street NW, DC, April 14, 1865" into the search engine and chew on my bottom lip as I hit Enter, because that date sounds very familiar. When the results come up, I feel like I've been punched in the throat.

The Lincoln a.s.sa.s.sination.

XP had a hand in the Lincoln a.s.sa.s.sination.

I sit back in my chair. Five minutes ago, I was hot, sweaty, and jumpy from all the adrenaline. Now I feel like I'm sitting in a freezer. My hands tremble.

Eagle Industries a.s.sa.s.sinated two presidents? I want to know the answer to this question, but I'm also beginning to understand the term "ignorance is bliss."

I put Lincoln to the side for a minute and go on to the next mission. 426 Marlborough Street right here in Boston on August 25, 1962. I type it in.

Nothing comes up. A few real estate links, a few present-day, city government PDFs, but nothing like Lincoln. Nothing obvious. That's weird. I delete the street address and just type in the date and the city. The first page of results is for a Red SoxIndians game, so maybe that's something? Fenway isn't that far away from Marlborough. But I keep scrolling. Page after page.

And then I get a really funny feeling in the pit of my stomach. On page five, there's an encyclopedia entry for the Boston Strangler. I click on it. A bunch of women were killed beginning in August of 1962. Is that related? Every instinct in my body is telling me this isn't about a baseball game. This has something to do with a serial killer.

And I don't like it. Not one little bit.

I keep reading and scroll down to the few paragraphs on the murders themselves. Fourteen single women, murdered in and around Boston, from 1962 to 1964. Each of them had willingly let the murderer into her house, only to be s.e.xually a.s.saulted and strangled, most often using her own nylon stockings. I shudder.

In October of 1964, a suspect was arrested. His name was Albert DeSalvo. He was convicted but, later, doubts began to swirl. It's now thought that the murders were the work of a number of killers, probably an original and one or more copycats.

I shudder again. Copycat killers. Those people are even more messed up than regular serial killers.

I look over the names and descriptions of the victims. They're all women who lived alone, but that's all they have in common. The youngest was 19. The oldest was 85. They're different races, different ethnicities, different socioeconomic backgrounds. We spent only a semester at Peel studying FBI profiling techniques, but even I could tell you this is likely not the work of only one person.

Is XP . . . a serial killer? Is it a side hobby? What is this?

I move on to the last mission, and I pause. Because I know the address. A first grader could tell you the address.

1600 Pennsylvania Avenue.

The White House.

And then I look at the date. I know it, too. Ariel just told me about it.

October 27, 1962. Right smack in the middle of the Cuban Missile Crisis.