It’s too dark in here, she heard herself saying. The words spilled out of her mouth, beyond her control.

No, Ali insisted. It’s got to be dark. That’s how it works.

It doesn’t always have to be the way you want it, you know, Ali? Spencer told her.

Close them, Ali answered, baring her teeth.

Spencer struggled to let light into the room. Ali let out a frustrated groan. But when Spencer glanced back at Ali, she realized that Ali wasn’t just angry. She’d frozen in place, her face drawn and ghost-pale, her eyes round. It was like she’d seen something awful.

Spencer turned back to the window, a shadow catching her eye. It was a tiny shard of a memory, barely anything. Spencer clung to the image now, desperate to remember whether it had really happened. And then…she saw. It was Ali’s reflection…except she wore a hood and carried a bulky camera. Her eyes were demonic and unblinking, out for murder. It was someone Spencer knew very well. She tried to say her name, but her lips wouldn’t work. She felt like she was choking.

The memory was rolling forward without her. Leave, she heard herself demand to Ali.

Fine, Ali answered.

“No!” Spencer told her old self. “Call Ali back! Keep her in the room! It’s…it’s her sister out there! And she wants to hurt Ali!”

But the memory careened on, out of Spencer’s grasp. Ali was at the door now. She turned around, giving Spencer a long look. Spencer let out a hoarse gasp. Suddenly, Ali didn’t quite look like the girl who was with them today.

Then Spencer’s gaze fell to the silver ring on the girl’s finger. Ali had said she hadn’t been wearing a ring that night, but there it was. Only, except instead of an A in the center, there was a C.

Why did Ali have on the wrong ring?

There was a tap on the window, and Spencer turned. The girl outside smiled sinisterly, running a hand along her eerily identical heart-shaped face. She held up the fourth finger on her right hand. She was wearing a ring, too—hers with the initial A. Spencer’s head felt like it was going to explode. Was Ali out there…and Courtney in here? How had that happened?

My memory’s playing tricks on me, she told herself. This didn’t happen. It’s just a dream.

The Ali at the door turned, her hand on the knob. Suddenly, her skin began to fade from pink to pale to white to ashen. “Ali?” Spencer called out cautiously. “Are you okay?”

Ali’s skin had begun to flake off in thick curls. “Does it look like I’m okay?” she snapped. She shook her head at Spencer. “I’ve been trying to tell you…”

“Trying to tell me?” Spencer echoed. “What do you mean?”

“All those dreams you’ve had about me? Don’t you remember?”

Spencer blinked. “I…”

Ali rolled her eyes. Her skin was peeling off faster now, revealing ropy muscles and bleached bones. Her teeth plunked to the floor like acorns. Her hair turned from golden blond to pale gray. Then it started to fall out in chunks. “You really are stupider than I thought, Spence,” she hissed. “You deserve this.”

“Deserve what?” Spencer screamed.

Ali didn’t answer. When she turned the knob, her hand flaked off at the elbow, as brittle as a dried flower. It landed on the wood floor and promptly dissolved into dust. Then the door slammed hard, the force resonating through Spencer’s body. It sounded close. Real. Memory and reality collided.

Spencer’s eyes sprang open. The bedroom was oppressively hot; sweat poured down her face. Her old friends sat cross-legged on the carpet, their faces docile and relaxed, their eyes sealed shut. They looked…dead.

“Guys?” Spencer called. No answer. She wanted to reach out and touch Hanna, but she was afraid.

The dream crackled in her brain. I’ve been trying to tell you, the girl in the vision said. The one who looked like the Ali she remembered…but the one who was wearing Courtney’s ring. All those dreams you’ve had about me. Don’t you remember?

Spencer did remember plenty of dreams about Ali. Sometimes, she even dreamed about two different Alis.

“No,” Spencer whispered perilously. She didn’t understand this. She blinked in the darkness, looking for her fourth friend.

“Ali?” she squeaked.

But Ali didn’t answer. Because Ali was gone.

29

THE LETTER UNDER THE DOOR

Aria heard a slam and jerked awake. Half the candles had blown out. A putrid smell filled the air. Her three old best friends were sitting on the carpet, staring at her.

“What’s going on?” she asked. “Where’s Ali?”

“We don’t know.” Emily looked terrified. “She…disappeared.”

“Maybe this is part of the reenactment?” Hanna suggested groggily.

“I don’t think so, guys.” Spencer’s voice trembled. “I think something’s really wrong.”

“Of course something’s wrong!” Emily cried. “Ali’s gone!”

“No,” Spencer said. “I think…I think something’s wrong with Ali.”

Aria gaped at her. “Ali?” Emily sputtered.

“What do you mean?” Hanna demanded.

“I think the girl at the window of the barn was Ali’s sister,” Spencer whispered, her voice thick with sobs. “I think that’s who killed her.”

Hanna wrinkled her brow. “I thought you said it was Melissa.”

“And no one killed Ali,” Emily added, narrowing her eyes. “She’s here.”

But Aria stared at Spencer, a tiny kernel of an idea forming in her head. She thought of those Polaroids again. It could have been a DiLaurentis face reflected in the window.

“Oh my God,” Aria whispered, remembering what that creepy medium had said to her a few weeks ago, as she stood over the hole where Ali’s body had been found: Ali killed Ali.

A bang thundered from downstairs. Everyone jumped and scuttled back into the corner, hugging one another tight. “What was that?” Hanna whispered.

There were a few more creaks and slams, then silence. Aria dared to look around the rest of the room. Someone must have opened the curtains, because moonlight spilled through the window onto the floor. That was when she noticed something she hadn’t seen before. Just inches from the door was a white envelope. It looked as though someone had recently slipped it through the crack.

“Um, guys?” she squeaked, pointing a shaky finger at it.

Everyone stared, too petrified to move. Finally, Spencer snatched it off the ground. Her fingers shook. She held the front of the envelope out for the rest of them to see.

To: Four Bitches. From: A.

Emily sank to her knees. “Oh my God. It’s Billy. He’s here.”

“It’s not Billy,” Spencer snapped.

“Then it’s Melissa,” Emily guessed frantically.

Spencer tore open the note. Lines and lines of type covered the page. As she read, her mouth twisted. “Oh my God.”

Hanna squinted. “This can’t be real.”

A cold, hard knot of certainty congealed in the pit of Aria’s stomach. There was something wrong. Taking a deep breath, she leaned in and read, too.

Once upon a time, there were two beautiful girls named Ali and Courtney—but one of them was crazy. And as you know, with a few magical twists of fate, Ali became Courtney for a while. But what you don’t know is that Courtney became Ali, too.

You heard me right, Pretty Little Losers…and it’s all because of you. Remember when you stalked me in my backyard for the Time Capsule flag? And remember that girl who trotted out to the lawn and talked to you? That wasn’t me. As you so astutely figured out, Courtney was home switching from the Radley to the Preserve that weekend. And oh, how poor widdle Courtney didn’t want to go. She had her neat, crazy little life at the Radley…and she didn’t want to start over in a new hospital.

If she had to start over somewhere, it was going to be in Rosewood. And start over she did. She was supposed to go to the Preserve the very morning she saw you skulking around my yard—and man, did she jump on the chance fast. One minute, she and I were arguing—I was so happy she was on her way out—and the next she was in the yard, pretending to be me, talking to you guys like you were BFFs. Talking about my flag as if she hadn’t been the one who’d stolen it first and ruined my masterpiece with that stupid wishing well. How was I supposed to know that everyone—my mom, my dad, even my brother—would think it was me out there and Courtney inside? How was I supposed to know my mom would grab me in the hall and say it’s time to go, Courtney? I pleaded with her that I was Ali, but my mom didn’t believe me, all because Courtney took my A-is-for-Ali ring when I wasn’t looking. My mom yelled outside to the girl who wasn’t Ali that we were leaving, and the girl who wasn’t Ali turned, smiled, and said, Bye!

Off we went. Courtney got my perfect life, and I got her wrecked one. Just like that.

She ruined everything. She put her lips all over Ian Thomas. She nearly got arrested for blinding prissy Jenna Cavanaugh. She ditched Naomi and Riley, the coolest girls at school. But the very worst thing she did in my name was choose four new best friends in their place. Girls she knew I wouldn’t look twice at, girls who weren’t special in any way. Girls who she knew would fall all over her, desperate for the opportunity to be in her exclusive club. The girls who’d help her get everything she wanted.

Any of this sound familiar, ladies?

But don’t worry. This little fairy tale can still have a happy ending for me. I saw to it that my sister paid for what she did. And now, so will you.

I tried to burn you. I tried to make you crazy. I tried to have you arrested. I’ve even messed with you this week—surprise! I flung myself at Aria’s boyfriend. I sent poor Hanna fake tickets to a certain fashion show. I let Em believe there was a happily-ever-after for us after all. Smooch! And Spencer…I have a surprise for you. Look closely! It’s right under your nose.

I suppose I should thank Courtney for her meticulous diary keeping. It helped me—and Mona—so much. It’s all led up to this big moment. The curtain’s about to go up, bitches, and the show is about to begin. Get ready to meet your maker. It won’t be long now.

Kisses!

A (the real one)

No one said anything for a long moment. Aria read the note several times before it sank in. She staggered backward, awkwardly bumping into the bureau. “Ali wrote this? Our Ali?”

“It isn’t our Ali,” Spencer said in a comatose voice. “It’s…the real Ali. Our Ali was…Courtney. The girl we knew is dead.”

“No.” Emily’s voice was choked. “It’s not possible. I don’t believe it.”

Suddenly, there was a snicker outside the door. Everyone shot up. Aria’s skin prickled.

“Ali?” Spencer cried out.

No answer.

Aria felt for her cell phone in her pocket, but the screen still said No Service Available. There was no landline in this room, either. Even if they hefted the window open and yelled, this property was so remote that no one would hear.