Adam’s cell phone buzzes. He checks it before flipping it around to show me the latest picture Katie sent of a girl with short black hair. This one has a nose piercing, heavy purple eye shadow. I shake my head. To Katie’s credit, she’s had five passing periods and already sent half a dozen pictures of girls who fit the description. Unfortunately, none of them have been close. Same with my yearbook search, though I’m not sure I’d recognize Cropped Hair Girl with a different haircut. More than once, I’ve wondered whether I hallucinated this morning, made associations that don’t exist.

I think about what Cullen said about me—that I used to pretend my twin sister was still alive. He was right. I remember creating elaborate scenes involving the two of us having tea parties in the basement and dance competitions around our swing set. I remember talking to her about the routines we performed. I pictured her facial expressions when I dictated instructions, basically making her my backup dancer. She would nod like it was a good idea. I guess that’s the thing with an imaginary dead sister: she’ll do whatever you want her to do.

Adam scrolls through Dopney’s online picture galleries, many of which showcase pictures of rare birds he’d come across. “The guy’s a homebody. Other than his two trips to Chicago, he’s completely boring—except for his bird fascination.” He flips his iPad so I can see the screen. “Look at this one,” he says, referencing a bird with a crazy wingspan about to take flight.

Adam’s phone buzzes again. I glance over, already prepared to dismiss it when I see a picture of Cropped Hair Girl—the actual one I’m looking for—pulling a book out of her locker. I jump in my chair and grab for the phone, but Adam beats me to it.

YES, he writes. Get her name.

How??

My body shakes with anticipation.

Adam stares at the picture. Never mind.

“What are you doing?”

Adam swipes at his device. The school’s homepage. The staff intranet. He keys in a password and continues clicking. “For the record, she’s wearing an army-green jacket, not an army jacket.”

He hits the link: Locker assignments.

“How are you doing this?”

Adam looks at me through his designer glasses. “Mrs. Greenberg’s an idiot. Her password is one, two, three, four, five. What’s the locker number?”

I grab Adam’s phone and zoom in on the number above the locker Cropped Hair Girl is rummaging through. “Two, five, one, zero.”

Adam smirks like he just did something sinister. “Amy London. Junior.”

I turn to the desktop. The real research begins. My hands shake as I type Amy London’s name into the Internet toolbar and hit enter.

Katie sends another picture. A caricature of herself in a Sherlock Holmes cap and a tweed cloak fluttering behind her like a cape. Beneath her sketch, she’s included #elementary.