One: Don’t Breathe In.

Emily Fields opened her eyes and looked around. She was lying in the middle of Spencer Hastings's backyard, surrounded by a wall of smoke and flames. Gnarled tree branches snapped and dropped to the ground with deafening thuds. Heat radiated from the woods, making it feel like it was the middle of July, not the end of January.

Emily's other old best friends, Aria Montgomery and Hanna Marin, were nearby dressed in soiled silk and sequined party dresses, coughing hysterically. Sirens roared behind them. Fire truck lights whirled in the distance. Four ambulances barreled onto the Hastingses' lawn, giving no heed to the perfectly shaped shrubs and flower beds.

A paramedic in a white uniform burst through the billowing smoke. "Are you all right?" he cried, kneeling down at Emily's side.

Emily felt as if she'd awakened from a yearlong sleep. Something huge had just happened…but what?

The paramedic caught her arm before she collapsed to the ground again. "You've inhaled a lot of smoke," he yelled. "Your brain isn't getting oxygen. You're lapsing in and out of consciousness." He placed an oxygen mask over her face.

A second person swam into view. It was a Rosewood cop Emily didn't recognize, a man with silvery hair and kind green eyes. "Is there anyone else in the woods besides the four of you?" he shouted over the din.

Emily's lips parted, scrambling for an answer that felt just beyond her reach. And then, like a light switching on, everything that had happened in the last few hours flooded back to her.

All those texts from A, the torturous new text message, insisting that Ian Thomas hadn't killed Alison DiLaurentis. The sign-in book Emily found at the Radley hotel party with Jason DiLaurentis's name all through it, indicating he might have been a patient back when the Radley was a mental hospital. Ian confirming on IM that Jason and Darren Wilden, the cop working on Ali's murder case, had been the ones to kill Ali—and warning them that Jason and Wilden would stop at nothing to keep them quiet.

And then the flicker. The horrible smell. The ten acres of woods bursting into flames.

They'd run blindly to Spencer's yard, catching up with Aria, who'd cut through the woods from her new house one street over. Aria had a girl with her, someone who'd been trapped in the fiery woods. Someone Emily thought she'd never see again.

Emily pulled the oxygen mask away from her face. "Alison," she shouted. "Don't forget Alison!"

The cop cocked his head. The paramedic cupped his head to his ear. "Who?"

Emily turned around, gesturing to where Ali had just been lying on the grass. She took a big step back. Ali was gone.

"No," she whispered. She wheeled around. The paramedics were loading her friends into ambulances. "Aria!" Emily screamed. "Spencer! Hanna!"

Her friends turned. "Ali!" Emily screeched, waving at the now-empty spot where Ali had been. "Did you see where Ali went?"

Aria shook her head. Hanna held her oxygen mask to her face, her eyes dating back and forth. Spencer's skin paled with terror, but then a bunch of EMTs surrounded her, helping her into the back of an ambulance.

Emily turned desperately to the paramedic. His face was backlit by the Hastingses' burning windmill. "Alison's here. We just saw her!"

The paramedic looked at her uncertainly. "You mean Alison DiLaurentis, the girl who…died?"

"She's not dead!" Emily wailed, nearly tripping over a tree root as she backed up. She gestured toward the flames. "She's hurt! She said someone was trying to kill her!"

"Miss." The cop placed a hand on her shoulder. "You need to settle down."

There was a snap a few feet away, and Emily pivoted. Four news reporters stood near the Hastingses' deck gaping. "Miss Fields?" a journalist called, running toward Emily and jabbing her microphone in Emily's face. A man with a camera and another guy holding a boom raced forward too. "What did you say? Who did you just see?"

Emily's heart pounded. "We've got to help Alison!" She looked around again. Spencer's yard was crawling with cops and EMTs. By contrast, Ali's old yard was dark and empty. When Emily saw a shape dart behind the wrought-iron fence that separated the Hastingses' yard from the DiLaurentises', her heart leapt. Ali? But it was only a shadow made by the flashing lights of a police car.

More journalists gathered, spilling from the Hastingses' front and side yards. A fire truck screamed up too, the firefighters leaping from the vehicle and pointing a huge hose at the woods. A bald, middle-aged reporter touched Emily's arm. "What did Alison look like?" he demanded. "Where has she been?"

"That's enough." The cop brushed everyone away. "Give her some space."

The reporter shoved the microphone at him. "Are you going to investigate her claim? Are you going to search for Alison?"

"Who set the fire? Did you see?" another voice screamed over the sound of the fire hoses.

The paramedic maneuvered Emily away from them. "We need to get you out of here."

Emily let out a fevered whimper, desperately staring at the empty patch of grass. The very same thing had happened when they saw Ian's dead body in the woods last week—one minute he was lying there, bloated and pale on the grass, and the next he was…gone. But it couldn't be happening again. It couldn't. Emily had spent years pining over Ali, obsessing over every contour of her face, memorizing every hair on her head. And that girl from the woods looked exactly like Ali. She had Ali's raspy, sexy voice, and when she wiped the soot from her face, it had been with Ali's small, delicate hands.

They were at the ambulance now. Another EMT clapped the oxygen mask back over Emily's mouth and nose and helped her onto a small cot inside. The paramedics buckled themselves in beside her. Sirens whooped, and the vehicle rolled slowly off the lawn. As they turned onto the street, Emily noticed a police car through the ambulance's back window, its sirens silenced, the headlights off. It wasn't driving toward the Hastingses' house, though.

She turned her attention back to Spencer's house, looking once more for Ali, but all she saw were curious bystanders. There was Mrs. McClellan, a neighbor from down the street. Hovering by the mailbox were Mr. and Mrs. Vanderwaal, whose daughter, Mona, had been the original A. Emily hadn't seen them since Mona's funeral a few months ago. Even the Cavanaughs were there, gazing at the flames in horror. Mrs. Cavanaugh had a hand resting protectively on her daughter Jenna's shoulder. Even though Jenna's sightless eyes were obscured by her dark Gucci sunglasses, it seemed like she was staring straight at Emily.

But Ali wasn't anywhere in the chaos. She'd vanished—again.