Lost And Found.

Ever have something really important just up and vanish without a trace? Like that vintage Pucci scarf you wore to the ninth-grade formal. It was around your neck the whole night, but when it was time to head home, poof. Gone. Or that gorgeous gold locket your grandmother gave you. Somehow it grew legs and just walked away. But lost things don't just disappear into thin air. They have to be somewhere.

Four pretty girls in Rosewood have lost very important things too. Things much bigger than a scarf or necklace. Like the trust of their parents. An Ivy League future. Purity. And they thought they lost their childhood best friend, too…but maybe not. Maybe the universe returned her, safe and sound. But just remember, the world has a way of balancing out: When something is given back, something else must be taken away.

And in Rosewood, that could be anything. Credibility. Sanity. Lives.

Aria Montgomery was the first to arrive. She tipped her bike onto the crushed-gravel drive, plopped down under a lavender weeping willow, and ran her fingers through the soft, clipped lawn. Just yesterday, the grass had smelled like summer and freedom, but after all that had happened, the scent no longer filled Aria with liberated glee.

Emily Fields appeared next. She was wearing the same faded, nondescript jeans and lemon yellow Old Navy tee she'd had on the night before. The clothes were wrinkled now, as if she'd slept in them. "Hey," she said listlessly, lowering herself down next to Aria. At the exact same moment, Spencer Hastings emerged from her front door, a solemn look on her face, and Hanna Marin slammed the door to her mom's Mercedes.

"So." Emily finally broke the silence when they were all together.

"So," Aria echoed.

Simultaneously, they turned and looked at the barn at the back of Spencer's yard. The night before, Spencer, Aria, Emily, Hanna, and Alison DiLaurentis, their best friend and leader, were supposed to have had their long-awaited, end-of-seventh-grade sleepover there. But instead of the party lasting until dawn, it had ended abruptly before midnight. Far from being the perfect kickoff to summer, it had been an embarrassing disaster.

None of them could make eye contact. Not could they look next door at the big Victorian house that belong to Alison's family. They were due over there any minute, but it wasn't Alison who'd invited them over today—it was her mother, Jessica. She'd called each girl mid-morning, saying Alison hadn't turned up after breakfast—was she at one of their houses? Ali's mom hadn't seemed too alarmed when they said no, but when she called back a few hours later, reporting that Ali still hadn't checked in, her voice was thin and high-pitched with distress.

Aria tightened her ponytail. "None of us saw where Ali went, right?"

They shook their heads. Spencer gently prodded at a purple bruise that had appeared on her wrist that morning. She had no idea when she'd hurt herself. There were a few scratches on her arms, too, as if she'd gotten tangled in a vine.

"And she didn't tell anyone where she was going?" Hanna asked.

Each girl shrugged. "She's probably off somewhere fun," Emily concluded in an Eeyore voice, hanging her head. The girls had nicknamed Emily "Killer," as in, Ali's personal pit bull. That Ali could have more fun with anyone else made her heart break.

"Nice of her to include us," Aria said bitterly, kicking at a clump of grass with her motorcycle boots.

The hot June sun beat down relentlessly on their winter-pale skin. They heard a splash from a backyard pool and the groan of a lawn mower in the distance. It was typical suburban summer bliss in Rosewood, Pennsylvania, a luxurious and pristine suburb about twenty miles from Philadelphia. Right now, the girls were supposed to be poolside at the Rosewood Country Club, ogling cute guys who went to their elite private school, Rosewood Day. They still could do that, but it felt weird to have fun without Ali. They felt adrift without her, like actresses without a director or marionettes without a puppeteer.

At last night's sleepover, Ali had seem more aggravated with them than usual. Distracted, too—she'd wanted to hypnotize them, but when Spencer insisted that the blinds be left open, Ali argued that they needed to be closed; then Ali abruptly left without saying good-bye. All the girls had a sinking feeling they knew why she'd left—Ali had found something better to do, with friends older and way cooler than they were.

Even though none of them would admit it, they'd sense this might be coming. Ali was the girl at Rosewood Day who set trends, topped every guy's Hottest Girl list, and decided who was popular and who was an undesirable Not It. She could charm anyone, from her sullen older brother, Jason, to the school's strictest history teacher. Last year, she'd plucked Spencer, Hanna, Aria, and Emily from obscurity and invited them into her inner sanctum. Things were perfect for the first few months, the five of them ruling the Rosewood Day hallways, holding court at sixth-grade parties, and always scoring the best booth at Rive Gauche at the King James Mall, kicking out less-popular girls who had been seated there first. But toward the end of seventh grade, Ali grew more and more distant. She didn't call them immediately when she got home from school. She didn't surreptitiously text them during class. When the girls talked to her, her eyes often looked glazed over, like her thoughts were elsewhere. The only things that interested Ali were their deepest, darkness secrets.

Aria glanced at Spencer. "You ran out of the barn after Ali last night. You seriously didn't see which way she went?" She had to yell over the sound of someone's weed whacker.

"No," Spencer said quickly, staring at her white J. Crew flip-flops.

"You ran out of the barn?" Emily tugged on one of her blondish-red ponytails. "I don't remember that."

"It was right after Spencer told Ali to leave," Aria informed them, a tinge of irritation in her voice.

"I didn't think she was going to," Spencer mumbled, plucking a rogue, bright yellow dandelion that had sprouted beneath the willow.

Hanna and Emily picked at their cuticles. The wind shifted, and the sweet smell of lilac and honeysuckle filled the air. The last thing they remembered was Ali's weird hypnosis: She counted down from one hundred, touched their foreheads with her thumb, and announced that they were in her power. What seemed like hours later, they'd awakened from a deep, disorienting sleep and Ali was gone.

Emily pulled her T-shirt collar over her nose, something she did when she was worried. Her shirt smelled faintly of All-Temperature Cheer and deodorant. "So what do we say to Ali's mom?"

"We cover," Hanna said matter-of-factory. "We say Ali's with her field hockey friends."

Aria tipped up her head, absently following the path of an airplane high in the cloudless blue sky. "I guess." But deep down, she didn't want to cover for Ali. The night before, Ali dropped some obvious hints about Aria's dad's horrible secret. Did she really deserve Aria's help now?

Emily's eyes followed a bumblebee as it meandered from flower to flower in Spencer's front garden. She didn't want to cover for Ali either. More than likely Ali was with her older field hockey friends—worldly, intimidating girls who smoked Marlboros out the windows of their Range Rovers and attended house parties with kegs. Was Emily terrible for wishing that Ali would get in trouble for running off with them? Was she a bad friend for wanting Ali all to herself?

Spencer scowled too. It wasn't fair that Ali just assumed they'd lie for her. Last night, before Ali could touch Spencer's forehead and put her under hypnosis, Spencer jumped up in protest. She was sick of Ali controlling them. She was sick of things being exactly the way Ali wanted.

"Come on, guys," Hanna urged, sensing everyone's reluctance. "We have to cover for Ali." The last thing Hanna wanted was to give Ali a reason to drop them—of that happened, Hanna would go back to being an ugly, chubby loser. And that wasn't the worst thing that could happen. "If we don't protect her, she might tell everyone about this…" Hanna trailed off, glancing across the street at the house where Toby and Jenna Cavanaugh lived. It had fallen into disrepair over the past year, the grass in the front yard badly in need of a mow, and the bottom of the garage doors covered in a thin layer of green, speckled mold.

Last spring, they'd accidentally blinded Jenna Cavanaugh while she and her brother were in their tree house. No one knew they'd set off the firework, though, and Ali had made them promise never to tell what really happened, saying the secret would bond their friendship forever. But what if they weren't friends anymore? Ali could be ruthless to people she didn't like. After she'd dropped Naomi Zeigler and Riley Wolfe out of nowhere at the beginning of sixth grade, she'd banned them from parties, made boys prank call their houses, and even hacked into their MySpace pages, writing half-mean, half-funny posts about their embarrassing secrets. If Ali ditched her four new friends, what promises would she break? What secrets would she tell?

The front door to the DiLaurentises' house opened, and Ali's mom stuck her head out onto the porch. Though normally stylish and polished, Mrs. DiLaurentis had thrown her pale blond hair into a sloppy ponytail. A pair of frayed shorts hung low on her ragged T-shirt stretched across her midriff.

The girls stood and walked up the stone path to Ali's door. As usual, the foyer smelled like fabric softener, and photos of Alison and her brother, Jason, lined the halls. Aria's gaze went immediately to Jason's senior picture, his longish hair pushed off his face, the corners of his lips curled up into just a hint of a smile. Before the girls could perform their usual ritual of touching the bottom right-hand corner of their favorite photo from their trip to the Poconos last July, Mrs. DiLaurentis swept them into the kitchen and gestured for them to sit at the big wood table. It felt weird to be in Ali's house without Ali here—almost like they were spying on her. There was evidence of her everywhere: a pair of turquoise Tory Burch wedges by the laundry room door, a travel-size bottle of Ali's favorite vanilla hand cream on the telephone table, and Ali's report card—all A's, of course—pinned to the stainless-steel refrigerator with a pizza-shaped magnet.

Mrs. DiLaurentis sat down with them and cleared her throat. "I know you girls were with Alison last night, and I need you to think really hard. Are you sure she didn't give you any hints about where she might have gone?"

The girls shook their heads, staring at the woven jute place mats. "I think she's with her field hockey friends," Hanna blurted out, when it seemed no one else was going to speak.

Mrs. DiLaurentis shredded a grocery list into small squares. "I already called all the girls on the team's telephone tree—and her friends from hockey camp. No one has seen her."

The girls exchanged alarmed glances. Nerves streaked through their chests, and their hearts began to thump a little faster. If Ali wasn't with any of her other friends, then where was she?

Mrs. DiLaurentis drummed her fingers on the table. Her nails looked uneven, as if she'd been biting them. "Did she mention coming home last night? I thought I saw her in the kitchen doorway when I was talking to…" She trailed off for a moment, casting her eyes to the back door. "She looked upset."

"We didn't know Ali came back into the house," Aria mumbled.

"Oh." Ali's mom's hands trembled as she reached for her coffee. "Has Ali ever talked about someone teasing her?"

"No one would do that," Emily said quickly. "Everyone loves Ali."

Mrs. DiLaurentis opened her mouth to protest but then changed her mind. "I'm sure you're right. And she never said anything about running away?"

Spencer snorted. "No way." Only Emily ducked her head. She and Ali sometimes talked about running away together. One of their fantasies about flying to Paris and adopting brand-new identities had recently been in heavy rotation. But Emily was sure Ali had never been serious.

"Did she ever seem sad?" Mrs. DiLaurentis went on.

Each of the girls' expressions grew more and more baffled. "Sad?" Hanna finally blurted. "Like…depressed?"

"Absolutely not," Emily stated, thinking about how gleefully Ali had pirouetted across the lawn the day before, celebrating the end of seventh grade.

"She'd tell us I something was bothering her," Aria added, although she wasn't quite sure if this was true. Ever since Ali and Aria had discovered a devastating secret about Aria's dad a few weeks ago, Aria had avoided being around Ali. She'd hoped that they could put it behind them at last night's sleepover.

The DiLaurentises' dishwasher grumbled, shifting into the next cycle. Mr. DiLaurentis wandered into the kitchen, looking bleary-eyed and lost. When he glanced at his wife, an uncomfortable expression came over his face,nana he quickly wheeled around and left, vigorously scratching his beakish, oversize nose.

"Are you sure you don't know anything?" Mrs. DiLaurentis asked. Worry lines creased her forehead. "I looked for her diary, thinking she might've written something in there about where she went, but I can't find it anywhere."

Hanna brightened. "I know what her diary looks like. Do you want us to go upstairs and search?" They'd seen Ali writing in her diary a few days ago, when Mrs. DiLaurentis sent them up to Ali's room without telling Ali first. Ali had been so absorbed in her diary that she'd seemed startled by her friends, as if she'd momentarily forgotten that she'd invited them over. Seconds later, Mrs. DiLaurentis had sent the girls downstairs because she wanted to lecture Ali about something, and when Ali emerged on the patio, she'd seemed annoyed they were there, like they'd done something wrong by staying at her house while her mom yelled at her.

"No, no, that's all right," Mrs. DiLaurentis answered, setting down her coffee cup fast.

"Really." Hanna scraped back her chair and started down the hall. "It's no trouble."

"Hanna," Ali's mom barked, her voice suddenly razor-sharp. "I said no."

Hanna halted under the chandelier. Something impossible to read rumbled beneath Mrs. DiLaurentis's skin. "Okay," Hanna said quietly, returning to the table. "Sorry."

After that, Mrs. DiLaurentis thanked the girls for coming over. They filed out one by one, blinking in the startlingly bright sun. In the cul-de-sac, Mona Vanderwaal, a loser girl in their grade, was making big figure eights on her on her Razor scooter. When she the girls, she waved. None of them waved back.

Emily kicked a loose brick on the walkway. "Mrs. D is overreacting. Ali's fine."

"She isn't depressed," Hanna insisted. "What a retarded thing to say."

Aria stuffed her hands into her miniskirt's back pockets. "What if Ali did run away? Maybe not because she was unhappy, but because there was somewhere cooler she wanted to be. She probably wouldn't even miss us."

"Of course she'd miss us," Emily snapped. And then she burst into tears.

Spencer looked over, rolling her eyes. "God, Emily. Do you have to do that right now?"

"Lay off her," Aria snapped.

Spencer turned her gaze to Aria, canvassing her up and down. "Your nose ring is crooked," she pointed out, more than a tinge of nastiness in her voice.

Aria felt for the stick-on, bedazzled nose stud on her left nostril. Somehow, it had slipped almost to her cheek. She pushed it back into position and then, in a rush of self-consciousness, pulled it off altogether.

There was a rustling noise, and then a loud crunch. They turned and saw Hanna reaching into her purse for a handful of Cheez-Its. When Hanna noticed them watching easily, she froze. "What?" she said, a halo of orange around her mouth.

Each girl stood silently for a moment. Emily blotted her tears. Hanna took another sneaky handful of Cheez-Its. Aria fiddled with the buckles of her motorcycle boots. And Spencer crossed her arms, looking bored with them. Without Ali there, the girls suddenly seemed so defective. Uncool, even.

A deafening roar sounded from Ali's backyard. The girls turned and saw a red cement truck positioned next to a large hole. The DiLaurentises were building a twenty-person gazebo. A scruffy, scrawny worker with a stubby blond ponytail raised his mirrored sunglasses at the girls. He gave them a lascivious smile, revealing a gold front tooth. A bald, beefy, heavily tattooed worker in a skimpy wifebeater and torn jeans whistled. The girls shivered uneasily—Ali had told them stories about how the workers were constantly calling out lewd comments as she passed. Then one of the workers signaled to the guy at the wheel of the cement mixer, and the truck slowly backed up. Slate gray concrete oozed down a long chute into the hole.

Ali had been telling them about this gazebo project for weeks. It was going to have a hot tub on one side and a fore pit on the other. Big plants, bushes, and trees would surround the whole thing so the gazebo would feel tropical and serene.

"Ali's going to love that gazebo," Emily said confidently. "She'll have the best parties there."

The others nodded cautiously. They hoped they'd be invited. They hoped this wasn't the end of an era.

And then they parted ways, each girl going home. Spencer wandered into her kitchen, gazing out the back windows at the barn where the dreadful sleepover had taken place. So what if Ali ditched them forever? Her friends might be devastated, but maybe it wouldn't be such a bad thing. Spencer was over Ali pushing her around.

When she heard a sniffle, she jumped. Her mother was sitting at the island counter, staring into space, her eyes glassy. "Mom?" Spencer softly, but her mother didn't answer.

Aria walked down the DiLaurentises' driveway. The family's trash cans sat on the curb, waiting for the Saturday garbage collection. One of the lids had fallen off, and Aria saw an empty prescription bottle sitting on top of a black plastic bag. The label was mostly scratched off, but Ali's name was printed there in block letters. Aria wondered if they were antibiotics or spring allergy meds—the pollen in Rosewood was brutal this year.

Hanna waited on one of the boulders in Spencer's front yard for her mom to pick her up. Mona Vanderwaal was riding her scooter around the cul-de-sac. Could Mrs. DiLaurentis be right? had someone dared to tease Ali, just like Ali and the others taunted Mona?

Emily grabbed her bike and walked to Ali's backwoods for the shortcut back to her house. the gazebo workers were taking a break. that same scrawny guy with the gold tooth was horsing around with someone sporting a wispy mustache, inattentive to the concrete as it flowed from the cement mixer into the hole. their cars—a dented Honda, two pickups, and a bumper sticker—slathered Jeep Cherokee—were parked along the curb. At the very end of the line was a vaguely familiar black vintage sedan. It was nicer than the others, and Emily could see her reflection in the shiny doors as she biked past. Her face looked pensive. What would she do if Ali didn't want to be her friend anymore?

As the sun rose higher in the sky, each girl wondered what would happen if Ali dropped them cold, like she had Naomi and Riley. But none of them paid any attention to Mrs. DiLaurentis's frantic questions. She was Ali's mom—it was her job to worry.

None of them could have predicted that by the following day, the DiLaurentises' front lawn would be filled with news vans and police cars. Nor could they have known where Ali truly was or whim she'd really planned on meeting when she'd run out of the barn that night. No, on that pretty June day, the first full day of summer vacation, they pushed Mrs. DiLaurentis's concerns aside. Bad things didn't happen in places like Rosewood. And they certainly didn't happen to girls like Ali. She's fine, they thought. She'll be back.

And three years later, maybe, just maybe, they were finally right.