IF MEMORY SERVES…

What if, all of a sudden, you could remember every single second of your entire life? And not just the major events everyone remembers—little things, too. Like that you and your best friend first bonded over hating the smell of rubber cement in third-grade art class. Or that the very first time you saw your eighth-grade crush, he was walking through the school courtyard, palming a soccer ball in one hand and an iPod Touch in the other.

But with every blessing comes a curse. With your spanking-new flawless memory, you’d also have to remember every fight with your BFF. You’d relive each time your soccer-loving crush sat next to someone else at lunch. With 20/20 memory, the past could suddenly get a whole lot uglier. Someone who seems like an ally now? Look again—could be they weren’t as nice as you thought. A friend you remember as always having your back? Oops! On closer inspection, not so much.

If four pretty girls in Rosewood were suddenly given perfect memories, they might know better who to trust and who to stay away from. Then again, maybe their pasts would make even less sense than before.

Memory’s a fickle thing. And sometimes we’re doomed to repeat the things we’ve forgotten.

There it was. The big Victorian house at the corner of the cul-de-sac, the one with the rose trellises along the fence and the tiered teak deck in the back. Only a select few had ever been inside, but everyone knew who lived there. She was the most popular girl in school. A girl who set trends, inspired passionate crushes, and made or broke reputations. A girl who every guy wanted to date and every girl wanted to be.

Alison DiLaurentis, of course.

It was a peaceful early September Saturday morning in Rosewood, Pennsylvania, an idyllic Main Line town about twenty miles from Philadelphia. Mr. Cavanaugh, who lived across the street from Alison’s family, strolled out to his yard to get the newspaper. The tawny golden retriever that belonged to the Vanderwaals a few doors down loped around the fenced-in backyard, barking at squirrels. Not a flower or a leaf was out of place…except for the four sixth-grade girls who all happened to be stealthily creeping into the DiLaurentises’ backyard at the same time.

Emily Fields hid among the tall tomato plants, tugging nervously on the strings of her Rosewood Long Course Swimming sweatshirt. She’d never trespassed on anyone’s property, let alone the backyard of the prettiest, most popular girl in school. Aria Montgomery ducked behind an oak tree, picking at the embroidery on the tunic her dad had brought back from yet another last-minute art history conference in Germany. Hanna Marin abandoned her bike by a boulder near the family’s shed, devising her plan of attack. Spencer Hastings crossed from her neighboring backyard and crouched behind a carefully pruned raspberry bush, inhaling the berries’ slightly sweet, slightly tangy smell.

Quietly, each girl stared into the DiLaurentises’ rear bay window. Shadows passed through the kitchen. There was a shout from the upstairs bathroom. A tree branch snapped. Someone coughed.

The girls realized they weren’t alone at exactly the same moment. Spencer noticed Emily fumbling by the woods. Emily spied Hanna squatting by the rock. Hanna glimpsed Aria behind the tree. Everyone marched to the center of Ali’s backyard and gathered in a tight circle.

“What are you guys doing here?” Spencer demanded. She’d known Emily, Hanna, and Aria since the Rosewood Public Library first-grade reading contest—Spencer had won, but all of them had participated. They weren’t friends. Emily was the type of girl who blushed when a teacher called on her in class. Hanna, who was now tugging at the waistband of her slightly too-small black Paper Denim jeans, never seemed comfortable with herself. And Aria—well, it looked like Aria was wearing lederhosen today. Spencer was pretty sure Aria’s only friends were imaginary.

“Uh, nothing,” Hanna shot back.

“Yeah, nothing,” Aria said, looking suspiciously at all of them. Emily shrugged.

“What are you doing?” Hanna asked Spencer.

Spencer sighed. It was obvious they were here for the same reason. Two afternoons ago, Rosewood Day, the elite prep school they attended, had announced the kickoff of its much-anticipated Time Capsule game. Each year, Principal Appleton cut a bright blue Rosewood Day flag into many pieces, upperclassmen hid them around town, and the teachers posted scavenger hunt–style clues to the whereabouts of each piece in the upper-and lower-school lobbies. Whoever found a piece got to decorate it however he or she wanted, and once every piece was found, the staff sewed the flag together again, held a big assembly honoring the winners, and buried it in a Time Capsule behind the soccer fields. Students who found Time Capsule pieces were legends—their legacies lived on forever.

It was hard to stand out at a school like Rosewood Day, and it was even harder to snag a piece of the Time Capsule flag. Only one loophole gave everyone a glimmer of hope: the stealing clause, which stated that it was legal to steal a piece from someone, right up until the piece’s time of burial. Two days ago, a certain beautiful somebody had bragged that one of the pieces was as good as hers. Now, four nobodies were hoping to take advantage of the stealing clause when she least expected it.

The thought of stealing Alison’s piece was intoxicating. On one hand, it was a chance to get close to her. On the other, it was an opportunity to show the prettiest girl at Rosewood Day that she might not always get everything she wanted. Alison DiLaurentis definitely deserved a reality check.

Spencer glared at the three other girls. “I was here first. That flag’s mine.”

“I was here before you,” Hanna whispered. “I saw you come out of your house only a few minutes ago.”

Aria stomped her purple suede boot, gawking at Hanna. “You just got here too. I was here before both of you.”

Hanna squared her shoulders and looked at Aria’s messy braids and chunky layered necklaces. “And who’s going to believe you?”

“Guys.” Emily jutted her pointy chin toward the DiLaurentis house and held a finger to her lips. There were voices coming from the kitchen.

“Don’t.” It sounded like Ali. The girls tensed.

“Don’t,” imitated a second high-pitched voice.

“Stop it!” Ali screeched.

“Stop it!” the second voice echoed.

Emily winced. Her older sister, Carolyn, used to squeakily imitate Emily’s voice the same exact way, and Emily hated it. She wondered if the second voice belonged to Ali’s older brother, Jason, a junior at Rosewood Day.

“Enough!” called a deeper voice. There was a wall-shaking thud and shattering glass. Seconds later, the patio door opened, and Jason stormed out, his sweatshirt flapping open, his shoes untied, and his cheeks flushed.

“Shit,” Spencer whispered. The girls scurried behind the bushes. Jason walked diagonally across the yard toward the woods, then stopped, noticing something to his left. An enraged expression slowly slithered across his face.

The girls followed his gaze. Jason was looking into Spencer’s backyard. Spencer’s sister, Melissa, and her new boyfriend, Ian Thomas, were sitting on the edge of the family’s hot tub. When they saw Jason staring, Ian and Melissa dropped hands. A few pregnant seconds crept by. Two days before, right after Ali bragged about the flag she was about to find, Ian and Jason had gotten in a fight over Ali in front of the entire sixth-grade class. Maybe the fight hadn’t ended.

Jason pivoted stiffly and marched into the woods. The patio door slammed again, and the girls ducked. Ali stood on the deck, looking around. Her long blond hair rippled down her shoulders, and her deep pink T-shirt made her skin look extra glowing and fresh.

“You can come out,” Ali yelled.

Emily widened her brown eyes. Aria ducked down further. Spencer and Hanna clamped their mouths shut.

“Seriously.” Ali walked down the deck steps, balancing perfectly on her wedge heels. She was the only sixth grader ballsy enough to wear high heels to class—Rosewood Day didn’t technically allow them until high school. “I know someone’s there. But if you’ve come for my flag, it’s gone. Someone already stole it.”

Spencer pushed through the bushes, unable to contain her curiosity. “What? Who?”

Aria emerged next. Emily and Hanna followed. Someone else had gotten to Ali before they did?

Ali sighed, plopping down on the stone bench next to the family’s small koi pond. The girls hesitated, but Ali gestured them over. Up close, she smelled like vanilla hand soap and had the longest eyelashes any of them had ever seen. Ali slid off her wedges and sank her petite feet into the soft green grass. Her toenails were painted bright red.

“I don’t know who,” Ali answered. “One minute, the piece was in my bag. The next minute, it was gone. I’d decorated it already and everything. I drew this really cool manga frog, the Chanel logo, and a girl playing field hockey. And I worked forever on the Louis Vuitton initials and pattern, copying the design straight from my mom’s handbag. I got it perfect.” She pouted at them, her sapphire blue eyes round. “The loser who took it is going to ruin it, I just know it.”

The girls murmured their condolences, each suddenly grateful that she hadn’t been the one to steal Ali’s flag—then she would be the loser she was complaining about.

“Ali?”

Everyone whipped around. Mrs. DiLaurentis stepped onto the deck. She looked as if she was on her way to a fancy brunch, dressed in a gray Diane von Furstenberg wrap dress and heels. Her gaze lingered on the girls for a moment, confused. It wasn’t as if they’d ever been in Ali’s backyard before. “We’re going now, okay?”

“Okay,” Ali said, smiling sweetly and waving. “Bye!”

Mrs. DiLaurentis paused, as if she wanted to say something else. Ali turned around, ignoring her. She pointed to Spencer. “You’re Spencer, right?”

Spencer nodded sheepishly. Ali looked searchingly at the others. “Aria,” Aria reminded Ali. Hanna and Emily introduced themselves too, and Ali nodded perfunctorily. It was a total Ali move—she obviously knew their names, but she was subtly saying that in the grand hierarchy of the Rosewood Day sixth-grade class, their names didn’t matter. They didn’t know whether to be humiliated or flattered—after all, Ali was asking their names now.

“So where were you when your flag was stolen?” Spencer asked, grappling for a question to keep Ali’s attention.

Ali blinked dazedly. “Uh, the mall.” She brought her pinkie finger to her mouth and started to chew.

“What store?” Hanna pressed. “Tiffany? Sephora?” Maybe Ali would be impressed that Hanna knew the names of the mall’s upscale shops.

“Maybe,” Ali murmured. Her gaze shifted to the woods. It seemed like she was looking for something—or someone. Behind them, the patio door slammed. Mrs. DiLaurentis had gone back inside the house.

“You know, the stealing clause shouldn’t even be permitted,” Aria said, rolling her eyes. “It’s just…mean.”

Ali pushed her hair behind her ears, shrugging. An upstairs light in the DiLaurentis house snapped off.