“My mom got it for me,” she said. Her voice sounded far away, even to her. “When I was little.”

For a moment the dingy storage unit faded, and she could feel Becky tying two of the octopus’s arms around Emma’s neck in the store so it hung down on her back like a cape. So he can protect you, Becky had explained, a rare smile lighting up her pretty face.

Emma blinked away her tears, and the dusty unit came back into focus. She tucked Socktopus under her arm, leaning down to pick up the envelope. For a moment she fumbled at the brad that held it closed, her fingers wooden and clumsy through the gloves. Then a pile of papers and photos slid out in one large stack. On top was a disc in a clear jewel case, labeled SUTTON IN AZ in red Sharpie.

“The video,” Ethan whispered.

She nodded, but she was already rifling through the pages behind the disc. There was a printout of the very first message Emma had sent Sutton. This will sound crazy, but I think we’re related. We look exactly the same, and we have the same birthday. Behind that was a page with Sutton’s e-mail and Facebook passwords. And behind that were photos—a thick stack of glossy black-and-white photos.

Emma had gotten so used to seeing Sutton’s face everywhere that for a moment, she thought the pictures were of her twin. But that wasn’t right—in the very top picture, the girl stood behind a ticket window. Emma’s heart skipped a beat. It was the New York–New York roller coaster in Vegas, where she’d worked the summer before coming to Tucson. In the picture she was busy counting change for a customer, completely unaware that someone had a lens trained on her.

The next picture caught her and Alex, running side by side on a trail through Red Rock Canyon. Another showed her reaching up to pull something off the top shelf at the public library. In a third she was walking into Clarice’s house, an expression of utter despondence on her face. The photos were grainy, taken surreptitiously and at awkward angles—but she was clear in all of them.

The old Emma had been an expert at staying anonymous and invisible, at keeping low to the ground so she couldn’t get hurt. The old Emma would have been embarrassed to realize that someone had been watching her all that time.

But the new Emma? The new Emma was pissed.

And so was I.

Emma shuffled the pictures to the back of the stack of paperwork, and leafed through the rest of the pages. She frowned at one that was simply a list of numbers. For a moment she didn’t know what she was looking at. Then she recognized one of the numbers.

It was the Mercers’ alarm code.