“I can trust you to put your shoes on by yourself, can’t I?” Mrs. Mercer said tightly, holding up a shoe by its T-strap. The label said MARC BY MARC JACOBS. “Be down for breakfast in two minutes.”

“Wait!” Emma protested, but Mrs. Mercer had already marched out of the room and slammed the door so hard that a snapshot of Sutton, Laurel, Charlotte, and Madeline fell from the bulletin board and landed facedown on the floor.

Emma stared around the silent room in panic. She darted to the ottoman where she’d left her cell phone. No new messages, said the screen. She raced to Sutton’s iPhone on the desk. There was one new text since she’d last checked, but it was only from Garrett: YOU VANISHED LAST NIGHT! SEE YOU IN FIRST PERIOD? XX!

“This is insane,” Emma whispered. The post she’d seen on Sutton’s Facebook Wall before she left Vegas popped into her head. Ever think about running away? I do. Could Sutton have run away thinking Emma could take her place long enough for her to get a head start? She strode barefoot out of Sutton’s bedroom and down the stairs.

The downstairs hallway was decorated with huge framed family photographs: school pictures, shots from family vacations to Paris and San Diego, and a portrait of the Mercer family at what looked like a fancy wedding in Palm Springs. Emma followed the sound of the morning news and the smell of coffee to the kitchen. It was a huge room with sparkling, floor-to-ceiling windows that looked out onto a brick patio and the mountains beyond. The counters were dark, the cabinets white, and there was a bunch of pineapple paraphernalia all over the room—wooden pineapples atop the cabinets, a ceramic pineapple cylinder that held spatulas and slotted spoons, a pineapple-shaped placard near the back door that said WELCOME!

Mrs. Mercer poured coffee at the sink. Sutton’s sister, Laurel, dissected a croissant at the kitchen table, dressed in a flowing printed top that looked identical to a shirt Emma had seen in Sutton’s closet last night. Mr. Mercer stepped in through the door, carrying plastic-wrapped copies of the Wall Street Journal and the Tucson Daily Star. Emma noticed his doctor’s coat, which said J MERCER, ORTHOPEDIC SURGERY. Like Mrs. Mercer, he was also a little older than most of the foster parents Emma had known, possibly a well-preserved fiftysomething. Emma wondered if they’d tried to have kids on their own before adopting Sutton. And what about Laurel? She had the same square jaw as Mrs. Mercer and the same round blue eyes as Mr. Mercer. Perhaps she was their biological daughter. Maybe the Mercers had finally conceived as soon as the adoption had gone through—Emma had read about that phenomenon somewhere.

Everyone looked up when Emma appeared in the doorway, including an enormous Great Dane. He rose from a striped doggie bed by the door and trotted over. He sniffed her hand, his big jowls grazing her skin. DRAKE, glinted a bone-shaped tag on his collar. Emma stood absolutely still. In seconds, Drake would probably start barking his head off, knowing Emma wasn’t who everyone thought she was. But then Drake snorted, turned, and trotted back to his bed.

A flash about Drake suddenly bubbled to the surface for me. His loud panting. The feel of his tongue on my face. How he’d howl goofily whenever an ambulance roared by. I felt an achy longing to wrap my arms around his big neck and kiss his cold, wet nose.

Mrs. Mercer set down a bottle of vitamins and walked over to Emma. “Drink.” She shoved a glass of orange juice toward Emma. “Do you have cash for lunch?”

“I need to tell you something,” Emma said loudly and sharply. Everyone stopped and stared at her. She cleared her throat. “I’m not Sutton. Your daughter is missing. She might have run away.”

A spoon clattered against a plate, and Mrs. Mercer’s eyebrows arched. Emma braced herself for something awful to happen—alarms to go off, fireworks to erupt, ninjas to emerge from the laundry room and take her down, anything that might indicate what she’d just revealed was very, very dangerous. But then Mr. Mercer just shook his head and took a sip of coffee from an ALOHA FROM HAWAII! pineapple mug. “And who, pray tell, might you be?” he asked.

“I’m her . . . long-lost twin sister, Emma. I was supposed to meet Sutton yesterday. But she’s . . . gone.”

Mrs. Mercer blinked rapidly. Mr. Mercer exchanged an incredulous look with Laurel.

“Save the creativity for English class.” Mrs. Mercer plucked a croissant from a platter on the island and pushed it toward Emma.

“I’m serious. My name is Emma,” she told them.

“Emma, hmm? And what’s your last name?”

“Pa—” Emma started, but Laurel slammed her coffee cup to the table. “You seriously don’t believe her, do you, Mom? She’s just trying to get out of school.”

“Of course I don’t believe her.” Mrs. Mercer pushed a folded piece of paper into Emma’s hand. “Here’s your schedule. Laurel, can you get Sleeping Beauty’s shoes and tennis bag from upstairs?”

“Why do I have to do it?” Laurel whined.

“Because I don’t trust your sister.” Mrs. Mercer grabbed a set of keys from a pineapple-shaped holder by the cordless phone. “She might fall back to sleep.”

“Fine.” Laurel groaned and scraped back her chair.

Emma stared blankly at the shiny brass buttons on Mrs. Mercer’s business suit, then at the new-agey crystal necklace at her throat. How could this be happening? Why didn’t they believe her? Was it that crazy?

Maybe. Even though I wanted my parents to believe what Emma was saying, it did kind of sound insane.

Laurel walked across the room toward the stairs. “Thanks a lot for last night, jerk,” she hissed at Emma as she passed.

Emma stepped back as if Laurel had just slapped her. Then she remembered Charlotte’s remark at the party. Did you ditch Laurel again? You’re a bad, bad sister. There was also the text from Laurel on Sutton’s phone: THANKS FOR NOTHING, BITCH.

“I didn’t ditch you.” Emma spun around and stared at Laurel’s receding back. “I was waiting for Sutton when Madeline dragged me to the party. I had no control.”

Laurel backtracked and stopped right in front of Emma. “Sure, Sutton. Just blow off the one thing I asked you weeks ago to do. I was basically stranded at Red Door. I bet you rigged it so you knew my phone was about to die, too, huh?” She had natural highlights and tiny freckles across her nose. Her wide jaw worked a fresh piece of Juicy Fruit gum. “Where’s your locket?”

Emma’s hand fluttered to her collarbone and she shrugged helplessly.

Laurel’s lips parted. She let out a low scoff. “But I thought it was so special to you,” she said icily. “Something no one else has. ‘The only way someone’s getting this from me is if they chop off my head!’” Her voice took on a singsong quality as she mimicked Sutton’s.

“Girls, don’t fight,” Mr. Mercer warned, reaching across the kitchen island to grab his leather briefcase and car keys.

“Yes, don’t fight,” Mrs. Mercer urged. “Just get those bags, okay? You have thirty seconds.” Laurel whirled around and started up the stairs. “Whose car are you taking? Sutton, is yours still at Madeline’s?”

Mrs. Mercer turned to Emma, waiting. “Uh, yes?” Emma guessed.

“We’ll take mine,” Laurel yelled from the floor above.

Mrs. Mercer ushered Emma out into the foyer. Emma’s nose twitched with the smell of Fracas perfume. She looked deep into the woman’s eyes, trying to convey exactly who she was . . . and exactly who she wasn’t. Surely she’d recognize her own daughter, right?

But Mrs. Mercer just pressed her hands on Emma’s shoulders. A tendon stood out in her neck. “Can you please go easy on us today?” She shut her eyes and let out a huge sigh. “We’re throwing you a huge birthday party in two weeks. Just once can you actually earn it?”

Emma flinched, then quickly nodded. Apparently they really didn’t believe her.

Laurel thundered back down the stairs with a bunch of sports bags and purses in her arms. She pushed the T-straps Mrs. Mercer had picked out, the tennis duffel, and a buttery-leather beige purse Emma didn’t recognize into Emma’s arms. Emma peeked inside the handbag. Sutton’s blue Kate Spade wallet and pink-cased iPhone were nestled into the inside pockets. At the bottom of the bag were pens, pencils, Dior mascara, and a spanking-new iPad. Emma raised her eyebrows. At least she’d finally find out what an iPad was like.

Mrs. Mercer opened the front door wide. “Get out of here.” Laurel strode to the porch, her car keys jingling in her hands. A silver RETURN TO TIFFANY & CO. keychain dangled from the ring. After shoving on her shoes, Emma followed. She had a feeling that if she didn’t, Mrs. Mercer would jab her out the door with the decorative rowing oar that stood in the corner of the foyer.

As soon as Emma stepped outside, sweat beaded at her forehead. Sprinklers hissed on the lawn across the street, and little kids in plaid school uniforms waited at the corner for the bus. Laurel glared at Emma over her shoulder as she walked across the driveway, her high heels making staccato clacks. “That was a lame way to try to get out of school.” She hit a button on the keychain remote. After two short bleeps, a black VW Jetta under the basketball hoop unlocked. “Your long-lost twin sister? Where’d you come up with that?”

Emma peered across the street again. She kept hoping to see Sutton saunter down the sidewalk, ready with an apology and an explanation. Bees swarmed impassively around the flowering bushes. A landscaping truck trundled past. The mountain range glowed in the rising sun, Sabino Canyon somewhere among it.

“Hello, space cadet?”

Emma flinched. Laurel walked toward her again, a small white envelope in her hands. SUTTON, it said on the front in tall capital letters. “It was under my wiper.” Laurel’s voice was tinged with bitterness. “Do you have another secret admirer?”

Emma considered the note for a moment. A few buds of pollen had stained the upper right corner. Should she open something that wasn’t hers? But Laurel kept staring, waiting, snapping her gum in Emma’s ear.

Finally Emma gave Laurel a look. “Do you mind giving me a little space?” It sounded like something Sutton might say.

Laurel sniffed and took one step away. Emma slid her finger under the flap on the envelope and pulled out a sheet of lined paper.

Sutton’s dead. Tell no one. Keep playing along . . . or you’re next.

Emma whipped around the yard, but the morning was eerily still. The school bus grumbled to the corner and picked up the little kids. As it pulled away, its squeaky brakes sounded like screams.

“What’s it say?” Laurel leaned over.

Emma quickly crumpled the note in her hand. “Nothing.” Her voice was barely audible.

Laurel’s lip curled in a snarl. Then she opened the passenger door and pointed to the seat. “Just get in.”

Emma did as she was told, dazedly slumping into the seat and staring straight ahead. Her heart pounded so hard she was afraid it might explode.

“You’re being so weird,” Laurel said, starting the car. “What’s wrong with you?”