Don’t run away from your ride when you’re stuck in the wilderness at midnight, I think. The hair on the back of my neck tingles.

It could be a wild animal. Or it could be the maniac who stole my Volvo and ran down Thayer. He could be back for more.

I hold my breath and listen. Far away, a police siren wails.

Then, there it is again, the same sound I heard before: leaves stirring, crunching underfoot. I stand up slowly, my heart in my throat. Carefully, I step toward the path that will lead me back to the park’s entrance.

That’s when my eyes catch movement in the trees. Something rushes toward me. I turn on my heel and sprint up the path before I can see what it is. My body is sore from everything that’s happened during this long, awful night. I can hear my pursuer behind me, crashing through the bushes. My shin slams straight into something—I don’t see what—and I fall on my hands and knees. I scrabble at the dirt feebly, trying to get back to my feet. But behind me I can hear my pursuer getting closer. I roll over just in time to see someone detach from the shadows and step into view.

It’s a woman. When she sees me, she stops and stares, breathing hard. Her black hair looks almost blue in the moonlight. Her face is pitted and sunken, her eyes deep holes in her skull. She wears a dirty waitressing uniform with a tear at the hem. She steps toward me and I crabwalk backward, the dirt stinging my hands. When I turn around, I realize I’ve backed myself against the canyon rock. I have nowhere to run.

“Wait,” the woman says, extending one of her hands toward me. When she gets close, I see that her eyes aren’t black like I thought, but bright, oceanic blue. There’s an eerie, predatory expression on her face, too—as if she knows I’m trapped and she likes it.

“Hello, Sutton.” Her voice is soft and gravelly, and as causal as if we’d talked a thousand times before. “I’m your mother. Becky.”

And then the memory collapses in on itself, and I’m left with nothing at all.

8

WHO ARE YOU?

Emma clutched the doorframe of the hospital room, her eyes locked on Becky’s, the sound of her mom’s voice saying her name echoing in her mind over and over. Emma. Emma. Emma.

Becky recognized her. In one glance, she had seen what Sutton’s friends and family could not—that Emma was not Sutton. Emma wanted to believe it was because Becky was her mother, the person who knew her best. Only, Becky didn’t know her best; Becky hadn’t known her for thirteen years. But that could only mean …

Our brains asked the same question at the same time: Did Becky know Emma couldn’t be Sutton because she’d done something to me?

I tried to squeeze one more moment from the memory I’d just recovered, to stay in it just a little longer, but nothing came. All I could see was Becky walking toward me out of the darkness. I didn’t know what it meant, but the expression on Becky’s face that night in the canyon left me chilled to the soul. But what kind of woman could kill her own daughter?

“Emma,” Becky whispered again. One of her front teeth was chipped, lending her smile a witchy look. Her arms spasmed at her sides.

Emma stepped away and shook her head, remembering that she wasn’t Emma, not here. “N-no,” she said. “I’m not Emma.”

Mr. Mercer put his hand on Emma’s shoulder. “Honey, this is Sutton. Remember? I sent you pictures. This is your daughter.”

“Yes, my daughter.” All of a sudden, Becky’s twitching turned into all-out writhing. Her feet kicked off the blankets, knocking over a small dinner tray next to the bed with a loud clatter.

The nurse nodded, and two enormous, linebacker-sized orderlies stepped into the room. For the first time, Emma noticed the stained leather restraints attached to the railings on the hospital bed. An orderly with a low ponytail leaned over the bed and pinned Becky down by her shoulders, while the other, whose hair was cut military-style, deftly tightened the leather straps around her arms and legs. They worked efficiently and quietly, as though Becky was a piece of furniture they were securing to a truck bed. Becky’s eyes darted back and forth, and her mouth opened and closed like a fish’s.

Emma swallowed hard, full of both pity and fear for the woman who’d abandoned her all those years ago—and who might have hurt her twin.

“Emma!” Becky wailed.

“My name’s not Emma,” Emma insisted, her voice loud and clear. “I’m Sutton.”

“You’re Emma!” Becky’s voice climbed higher and higher. She sounded almost as if she were pleading. “Emma! Emma, Emma, Emma, Emma …” Fat tears streaked down her cheeks.

Mr. Mercer leaned in. “Who’s Emma, Becky? Can you tell us?”

Becky just shook her tear-streaked face back and forth violently. Her whole body trembled and strained against the ties.

Her vacant expression triggered one of Emma’s last memories of her mom. At her preschool graduation, which Becky had missed, Emma won a good citizenship award for keeping her desk cleaner than anyone else’s. She’d tagged along with the families of her classmates to get ice cream afterward and had tried to pretend she didn’t hear the other parents’ whispers of “irresponsible” and “not all there.” She’d gotten mint chocolate chip, which was Becky’s favorite flavor, to help pretend that her mother was with her. Later, when she let herself into their motel room with the key she kept on a Hello Kitty lanyard in her backpack, Becky was in bed staring at the ceiling. Emma carefully put away her backpack and shoes in the closet. She crawled into bed next to her mother and nestled at her side. Becky stared at her as if she’d never seen her before.

“Which one are you again?” she asked.

Emma smiled. This was a game she knew—sometimes her mother teased her, pretending she didn’t know who she was.

“I’m Emma!” she said, touching her own forehead. “Which one are you?”

At that, Becky started to cry. “I’m your mother,” she whispered, hugging Emma close to her chest.

Three days later, she left Emma at the sleepover.

“Emma, Emma, Emma,” whimpered Becky. Tears ran down her face, leaving tracks in the grime on her cheeks. Emma—little-girl Emma—wanted to step forward with a Kleenex to gently wipe her mother’s face. But in the real world she couldn’t seem to move. She didn’t want to go near the deranged woman flailing on the hospital bed.

“There now, Ms. Mercer,” said a gentle voice with a soft Anglo-Indian accent. A middle-aged man in a white coat stepped past the nurse, a syringe in his hand. When she saw the needle, Becky groaned. She shook her head wildly, her hair whipping across her face. “This will only hurt for a second,” said the doctor, quickly sliding the needle into her arm.

Seconds later, Becky’s body relaxed. Her eyes unfocused and her head lolled to face the wall.

“Thank you, Dr. Banerjee,” Mr. Mercer said wearily.

Emma looked up at the doctor in surprise—it was Nisha’s father, a short man with a round face, thick glasses, and a sad expression. His wife had passed away not long ago. Every time Emma had seen him, he’d looked so lost.

Dr. Banerjee ushered Mr. Mercer and Emma out of the room. “Let’s go into the hall so she can rest.”

“You’re just going to leave the restraints on her?” Emma blurted out.

Dr. Banerjee looked at her steadily. His red-rimmed eyes were magnified behind his lenses. “They’re for her own protection, Sutton. I promise, we will do our best to make her comfortable. But right now she is a danger to herself and to others.”

They followed him into the hallway. A low bench ran against the wall under the Monet print, and he gestured for them both to sit. Mr. Mercer sank onto the bench gratefully, but Emma shook her head. Dr. Banerjee turned to face them.

“This is the worst I’ve seen her in a long time,” he said, exhaling heavily. He opened a large file that had been clamped beneath his arm and rifled through it. Becky’s records, Emma realized. She glanced at Mr. Mercer questioningly.

“Dr. Banerjee has treated Becky several times over the years, when she’s been in town,” he explained.

She nodded slowly. “How did she end up in here today?” she asked Dr. Banerjee.

“She was arrested,” Nisha’s father explained.

Mr. Mercer rubbed his face, as if trying to scrub the information away. Finally, he looked up at Dr. Banerjee again. “Did she hurt anyone?”

The other man sat down across from him and took what Emma recognized as a police report from the file. “No, thankfully. She pulled a knife on a man at the mall downtown. She was confused, agitated. Several shopkeepers reported that she’d been in their stores earlier in the day asking bizarre questions. But mall security managed to get the knife from her without anyone being hurt.”

I remembered the eerie look on my mother’s face in the canyon the night we met. If she could wave a knife at someone, maybe she could do worse. Maybe she had done worse.

“When was the last time you saw her?” asked Dr. Banerjee.

Mr. Mercer shook his head. “About two months ago. She checked out of her hotel, so I assumed she’d left town, like she usually does. But then she called me from a motel just last week, so I’m not sure where she’s been.”

Dr. Banerjee wiped his glasses on the sleeve of his coat. “I’m sorry to tell you this, but she seems to have been living out of her car—the police found it in the parking lot. She’s off her medication again. I’m not sure for how long, but you know how bad she gets.”

Mr. Mercer and Dr. Banerjee continued to talk in low voices about Becky’s prognosis and a potential treatment plan, and Mr. Mercer asked whether he should talk to an attorney in case anyone at the mall pressed charges. But Emma was only half listening. She glanced back to the room that held her mother, drugged and silent. Then her eyes fell on the folder on Dr. Banerjee’s lap, bristling with medical records and arrest reports.

Emma imagined her two worlds, side by side like the twin images in a stereoscope. Was Becky her sad, beautiful mother, loving but tragic? Or was she a knife-wielding maniac, a woman so wild she deserved to be strapped to a bed? Her hands closed into fists. She wasn’t the adoring little-girl Emma anymore, and she couldn’t afford to be a bitter teenage Emma coming to terms with her mother’s sudden reappearance. She was a different person altogether. She was the Emma who’d been channeling Sutton. She was a tough and practical Emma who had to fight to survive, who had to ask difficult questions and learn truths she wasn’t sure she wanted to know. She was the Emma who was going to solve a murder, and to do that, she knew she had to find out what was in that file.

I wanted to see whatever was in that folder as badly as she did. Now she just had to figure out a way to get it.

9

WHITE LIES AND ALIBIS

It was just after midnight when Mr. Mercer pulled the car into the driveway and killed the motor. The lights were on in the kitchen—Mrs. Mercer had obviously waited up for them—but he made no move to get out of the car. He and Emma sat in silence, neither one looking directly at the other. With the AC off, the air quickly became heavy around them.