How It All Started.

Imagine it's a couple of years ago, the summer between seventh and eighth grade. You're tan from lying out next to your rock-lined pool, you've got on your new Juicy sweats (remember when everyone wore those?), and your mind's on your crush, the boy who goes to that other prep school whose name we won't mention and who folds jeans at Abercrombie in the mall. You're eating your Cocoa Krispies just how you 'em—doused in skim milk—and you see this girl face on the side of the milk carton. Missing. She's cute—probably cuter than you—and has a feisty look in her eyes. You think, Hmm, maybe she likes soggy Cocoa Krispies too. And you bet she'd think Abercrombie boy was a hottie as well. You wonder how someone so...well, so much like you went missing. You thought only girls who entered beauty pageants ended up on the sides of milk cartons.

Well, think again.

Aria Montgomery burrowed her face in her friend Alison DiLaurentis's lawn. "Delicious," she murmured.

"Are you smelling the grass?" Emily Fields called from behind her, pushing the door of her mom's Volvo wagon closed with her long, freckly arm.

"It smells good." Aria brushed her pink-striped hair and breathed in the warm early-evening air. "Like summer."

Emily waved 'bye to her mom and pulled up the blah jeans that were hanging on her skinny hips. Emily had been a competitive swimmer since Tadpole League, and even though she looked great in a Speedo, she never wore anything right or remotely cute like the rest of the girls in her seventh-grade class. That was because Emily's parents insisted that one built character from the inside out. (Although Emily was pretty certain that being forced to hide her Irish Girls Do It Better baby tee at the back of her underwear drawer wasn't exactly character enhancing.)

"You guys!" Alison pirouetted through the front yard. Her hair was bunched up in a messy ponytail, and she was still wearing her rolled-up field hockey kilt from the team's end-of-the-year party that afternoon. Alison was the only seventh grader to make the JV team and got rides home with the older Rosewood Day School girls, who blasted Jay-Z from their Cherokees and sprayed Alison with perfume before dropping her off so that she wouldn't smell like the cigarettes they'd all been smoking.

"What am I missing?" called Spencer Hastings, sliding through a gap in Ali's hedges to join the others. Spencer lived next door. She flipped her long, sleek dark-blond ponytail over her shoulder and took a swig from her purple Nalgene bottle. Spencer hadn't made the JV cut with Ali in the fall, and had to play on the seventh-grade team. She'd been on a year-long field hockey binge to perfect her game, and the girls knew she'd been practicing dribbling in the backyard before they arrived. Spencer hated when anyone was better at anything than she was. Especially Alison.

"Wait for me!"

They turned to see Hanna Marin climbing out of her mom's Mercedes. She stumbled over her tote bag and waved her chubby arms wildly. Ever since Hanna's parents had gotten a divorce last year, she'd been steadily putting on weight and outgrowing her old clothes. Even though Ali rolled her eyes, the rest of the girls pretended not to notice. That's just what best friends do.

Alison, Aria, Spencer, Emily, and Hanna bonded last year when their parents volunteered them to work Saturday afternoons at Rosewood Day School's charity drive—well, except for Spencer, who volunteered herself. Whether or not Alison knew about the other four, the four knew about Alison. She was perfect. Beautiful, witty, smart. Popular. Boys wanted to kiss Alison, and girls—even older ones—wanted to be her. So the first time Ali laughed at one of Aria's hokes, asked Emily a question about swimming, told Hanna her shirt was adorable, or commented that Spencer's penmanship was way neater than her own, they couldn't help but be, well...dazzled. Before Ali, the girls had felt like pleated, high-waisted mom jeans—awkward and noticeable for all the wrong reasons—but then Ali made them feel like the most perfect-fitting Stella McCartneys that no one could afford.

Now, more than a year later, on the last day of seventh grade, they weren't just best friends, they were the girls of Rosewood Day. A lot had happened to make it that way. Every sleepover they had, every field trip, had been a new adventure. Even homeroom had been memorable when they were together. (Reading a steamy note from the charity crew captain to his math tutor over the PA system was now a Rosewood Day legend.) But there were other things they all wanted to forget. And there was one secret they couldn't even bear to talk about. Ali said that secrets were what bonded their five-way best-friendship together for eternity, if that was true, they were going to be friends for life.

"I'm so glad this day is over." Alison moaned before gently pushing Spencer back through the gap in the hedges. "Your barn."

"I'm so glad seventh grade is over," Aria said as she, Emily, and Hanna followed Alison and Spencer toward the renovated barn-turned-guest house where Spencer's older sister, Melissa had lived for her junior and senior years of high school. Fortunately, she'd just graduated and was headed to Prague this summer, so it was all theirs for the night.

Suddenly they heard a very squeaky voice. "Alison! Hey, Alison! Hey, Spencer!"

Alison turned to the street. "Not it," she whispered.

"Not it," Spencer, Emily, and Aria quickly whispered.

Hanna frowned. "Shit."

It was this game Ali had stolen from her brother, Jason, who was a senior at Rosewood Day, Jason and his friends played it at inter-prep school field parties when scoping out girls. Being the last to call out "not it" meant you had to entertain the ugly girl for the night while your friends got to hook up with her hot friends—meaning, essentially, that you were as lame and unattractive as she was. In Ali's version, the girls called "not it" whenever there was anyone ugly, uncool, or unfortunate near them.

This time, "not it" was for Mona Vanderwaal—a dork from down the street whose favorite pastime was trying to befriend Spencer and Alison—and her two freaky friends, Chassey Bledsoe and Phi Templeton. Chassey was the girl who'd hacked into the school's computer system and then told the principal how to better secure it, and Phi Templeton went everywhere with a yo-yo—enough said. The three stared at the girls from the middle of the quiet, suburban road. Mona was perched on her Razor scooter, Chassey was on the black mountain bike, and Phi was on foot—with her yo-yo, of course.

"You guys want to come over and watch Fear Factor?" Mona called.

"Sorry," Alison simpered. "We're kind of busy."

Chassey frowned. "Don't you want to see when they eat the bugs?"

"Gross!" Spencer whispered to Aria, who then started pretending to eat invisible lice off Hanna's scalp like a monkey.

"Yeah, I wish we could." Alison tilted her head."We've planned this sleepover for a while now. But maybe next time?"

Mona looked at the sidewalk. Yeah, okay."

"See ya." Alison turned around, rolling her eyes, and the other girls did the same.

They crossed through Spencer's back gate. To their left was Ali's neighboring backyard, where her parents were building a twenty-seat gazebo for their lavish outdoor picnics. "Thank God the workers aren't here," Ali said, glancing at a yellow bulldozer.

Emily stiffened. "Have they been saying stuff to you again?"

"Easy there, Killer," Alison said. The others giggled. Sometimes they called Emily "Killer," as in Ali's personal pit bull. Emily used to find it funny, too, but lately she wasn't laughing along.

The barn was just ahead. It was small and cozy and had a big window that looked out on Spencer's large, rambling farm, which had its own very windmill. Here in Rosewood, Pennsylvania, a little suburb about twenty miles from Philadelphia, you were more likely to live in a twenty-five-room farmhouse with a mosaic-tiled pool and hot tub, like Spencer's house, than a prefab McMansion. Rosewood smelled like lilacs and mown grass in the summer and clean snow and wood stoves in the winter. It was full of lush, tall pines, acres of rustic family-run farms, and the cutest foxes and bunnies. It had fabulous shopping and Colonial-era estates and parks for birthday, graduation, and just-'cause-we-feel-like-it fetes. And Rosewood boys were gorgeous in that glowing, healthy, just-stepped-out-of-an-Abercrombie-catalog way. This was Philadelphia's Main Line. It was full of old, noble bloodlines, older money, and practically ancient scandals.

As they reached the barn, the girls heard giggles coming from inside. Someone squealed, "I said, stop it!"

"Oh God," Spencer moaned. "What is she doing here?"

As Spencer peeked through the keyhole, she could see Melissa, her prim and proper, excellent-at-everything older sister, and Ian Thomas, her tasty boyfriend, wrestling on the couch. Spencer kicked at the door with the heel of her shoe, forcing it open. The barn smelled like moss and slightly burned popcorn. Melissa turned around.

"What the fu—?" she asked. Then she noticed the others and smiled. "Oh, hey guys."

The girls eyed Spencer. She constantly complained that Melissa was a venomous super-bitch, so they were always taken aback when Melissa seemed friendly and sweet.

Ian stood up, stretched and grinned at Spencer. "Hey."

"Hi, Ian," Spencer replied in a much brighter voice. "I didn't know you were here."

"Yeah, you did." Ian smiled flirtatiously. "You were spying on us."

Melissa readjusted her long blond hair and black silk headband, staring at her sister. "So, what's up?" she asked, a little accusingly.

"It's just... I didn't mean to barge in...," Spencer sputtered. "But we were supposed to have this place tonight."

Ian playfully hit Spencer on the arm. "I was just messing with you," he teased.

A patch of red crept up her neck. Ian had messy blond hair, sleepy-looking hazelnut-colored eyes, and totally gropeworthy stomach muscles.

"Wow," Ali said in a too-loud voice. All heads turned to her. "Melissa, you and Ian make the kuh-yoo-test couple. I've never told you, but I've always thought it. Don't you agree, Spence?"

Spencer blinked. "Um," she said quietly.

Melissa stared at Ali for a second, perplexed, and then turned back to Ian. "Can I talk to you outside?"

Ian down his Corona as the girls watched. They only ever drank super-secretively from the bottles in their parent's liquor cabinets. He set the empty bottle down and offered them a parting grin as he followed Melissa outside. "Adieu, ladies." He winked before closing the door behind him.

Alison dusted her hands together. "Another problem solved by Ali D. Are you going to thank me now, Spence?"

Spencer didn't answer. She was too busy looking out the barn's front window. Lightning bugs had begun to light up the purplish sky.

Hanna walked over to the abandoned popcorn bowl and took a big handful. "Ian's so hot. He's, like, hotter than Sean." Sean Ackard was one of the cutest guys in their grade and the subject of Hanna's constant fantasies.

"You know what I heard?" Ali asked, flopping down on the couch. "Sean really likes girls who have good appetites."

Hanna brightened. "Really?"

"No." Alison snorted.

Hanna slowly dropped the handful of popcorn into the bowl.

"So, girls," Ali said. "I know the perfect thing we can do."

"I hope we're not streaking again." Emily giggled. They'd done that a month earlier—in the freezing frickin' cold—and although Hanna had refused to strip down to less than her undershirt and day-of-the-week panties, the rest of them had run through a nearby barren cornfield without a lick on.

"You loved that a little too much," Ali murmured. The smile faded from Emily's lips. "But no—I was leaving this for the last day of school. I learned how to hypnotize people."

"Hypnotize?" Spencer repeated.

"Matt's sister taught me," Ali answered, looking at the framed photos of Melissa and Ian on the mantel. Her boyfriend of the week, Matt, had the same sandy-colored hair as Ian.

"How do you do it?" Hanna asked.

"Sorry, she swore me to secrecy," Ali said, turning back around. "You want to see if it works?"

Aria frowned, taking a seat on a lavender floor pillow. "I don't know..."

"Why not?" Ali's eyes flickered to a stuffed pig puppet that was peeking out of Aria's purple sweater-knit tote bag. Aria was always carrying around weird things—stuffed animals, random pages torn out of old novels, postcards of places she'd never visited.

"Doesn't hypnosis make you say stuff you don't want to say?" Aria asked.

"Is there something you can't tell us?" Ali responded. "And why do you still bring that pig puppet everywhere?" She pointed at it.

Aria shrugged and pulled the stuffed pig out of her bag. "My dad got me Pigtunia in Germany. She advises me on my love life." She stuck her hand into the puppet.

"You're shoving your hand up its butt! Ali squealed and Emily started to giggle. "Besides, why do you want to carry around something your dad gave you?"

"It's not funny," Aria snapped, whipping her head around to face Emily.

Everyone was quiet for a few seconds, and the girls looked blankly at one another. This had been happening a lot lately: Someone—usually Ali—mentioned something, and someone else got upset, but everyone was too shy to ask what in the world was going on.

Spencer broke the silence. "Being hypnotized, um, does sound sort of sketch."

"You don't know anything about it," Alison said quickly. "C'mon. I could do it to you all at once."

Spencer picked at the waistband of her skirt. Emily blew air through her teeth. Aria and Hanna exchanged a look. Ali was always coming up with stuff for them to try—last summer, it was smoking seeds to see if they'd hallucinate, and this past fall they'd gone swimming in Pecks Pond, even though a dead body was once discovered there—but the thing was, they often didn't want to do the things that Alison made them do. They all loved Ali to death, but they sometimes hated her too—for bossing them around and for the spell she'd cast on them. Sometimes in Ali's presence, they didn't feel real exactly. They felt kind of like dolls, with Ali arranging their every move. Each of them wished that, just once, she had the strength to tell Ali no.

"Puh-leeeeeze?" Ali asked. "Emily, you want to do it, right?"

"Um..." Emily's voice quivered. "Well..."

"I'll do it," Hanna butted in.

"Me too," Emily said quickly after.

Spencer and Aria reluctantly nodded. Satisfied, Alison shut off all the lights with a snap and lit several sweetly scented vanilla votive candles that were on the coffee table. Then she stood back and hummed.

"Okay, everyone, just relax," she chanted, and the girls arranged themselves in a circle on the rug. "Your heartbeat's slowing down. Think calm thoughts. I'm going to count down from one hundred, and as soon as I touch all of you, you'll be in my power."

"Spooky." Emily laughed shakily.

Alison began. "One hundred...ninety-nine...ninety-eight..."

Twenty-two...

Eleven...

Five...

Four...

Three...

She touched Aria's forehead with the fleshiest part of her thumb. Spencer uncrossed her legs. Aria twitched her left foot.

"Two..." She slowly touched Hanna, then moved toward Spencer. "One."

Spencer's eyes sprang open before Alison could reach her. She jumped up and ran to the window.

"What're you doing?" Ali whispered. "You're ruining the moment."

"It's too dark in here." Spencer reached up and opened the curtains.

"No." Alison lowered her shoulders. "It's got to be dark. That's how it works."

"C'mon. No it doesn't." The blink stuck; Spencer grunted to wrench it free.

"No. It does."

Spencer put her hands on her hips. "I want it light. Maybe everyone does."

Alison looked at the others. They all still had their eyes closed.

Spencer wouldn't give it. "It doesn't always have to be the way you want it, you know, Ali?"

Alison barked out a laugh. "Close them!"

Spencer rolled her eyes. "God, take a pill."

"You think I should a pill?" Alison demanded.

Spencer and Alison stared at each other for a few moments. It was one of those ridiculous fights that could have been about who saw the new Lacoste polo dress at Neiman Marcus first or whether honey-colored highlights looked too brassy, but it was really about something else entirely. Something way bigger.

Finally, Spencer pointed at the door. "Leave."

"Fine." Alison strode outside.

"Good!" But after a few seconds passed, Spencer followed her. The bluish evening air was still, and there weren't any lights on in her family's main house. It was quiet—even the crickets were quiet—and Spencer could hear herself breathing. "Wait a second!" she cried after a moment, slamming the door behind her. "Alison!"

But Alison was gone.

When she heard the door slam, Aria opened her eyes.

"Ali?" she called. "Guys?" No answer.

She looked around. Hanna and Emily sat like lumps on the carpet, and the door was open. Aria moved out to the porch. No one was there. She tiptoed to the edge of Ali's property. The woods spread out in front of her and everything was silent.

"Ali?" she whispered. Nothing. "Spencer?"

Inside, Hanna and Emily rubbed their eyes. "I just had the weirdest dream," Emily said. "I mean, I guess it was a dream. It was really quick. Alison fell down this really deep well, and there were all these giant plants."

"That was my dream too!" Hanna said.

"It was?" Emily asked.

Hanna nodded. "Well, kind of. There was a big plant in it. And I think I saw Alison too. It might've been her shadow—but it was definitely her."

"Whoa," Emily whispered. They stared at each other, their eyes wide.

"Guys?" Aria stepped back through the door. She looked very pale.

"Are you okay?" Emily asked.

"Where's Alison?" Aria creased her forehead. "And Spencer?"

"We don't know," Hanna said.

Just then, Spencer burst back into the house. All the girls jumped. "What?" she asked.

"Where's Ali?" Hanna asked quietly.

"I don't know," Spencer whispered. "I thought...I don't know."

The girls fell silent. All they could hear were the tree branches sliding across the window. It sounded like someone scraping her long fingernails against a plate.

"I think I want to go home," Emily said.

The next morning, they still hadn't heard from Alison. The girls called one another to talk, a four-way call this time instead of five.

"Do you think she's mad at us?" Hanna asked. "She seemed weird all night."

"She's probably at Katy's," Spencer said. Katy was one of Ali's field hockey friends.

"Or maybe she's with Tiffany—that girl from camp?" Aria offered.

"I'm sure she's somewhere having fun," Emily said quietly.

One by one, they got calls from Mrs. DiLaurentis, asking if they'd heard from Ali. At first, the girls all covered for her. It was the unwritten rule: They'd covered for Emily when she snuck in after her 11 P.M. weekend curfew; they'd fudged the truth for Spencer when she borrowed Melissa's Ralph Lauren duffel coat and then accidentally left it on the seat of a SEPTA train; and so on. But as each one hung up with Mrs. DiLaurentis, a sour feeling swelled in her stomach. Something felt horribly wrong.

That afternoon, Mrs. DiLaurentis called again, this time in a panic. By that evening, the DiLaurentises had called the police, and the next morning there were cop cars and news vans camped out on the DiLaurentises' normally pristine front lawn. It was a local news channel's wet dream: a pretty rich girl, lost in one of the safest upper-class towns in the country.

Hanna called Emily after watching the first nightly Ali news report. "Did the police interview you today?"

"Yeah," Emily whispered.

"Me too. You didn't tell them about..." She paused. "About The Jenna Thing, did you?"

"No!" Emily gasped. "Why? Do you think they know something?"

"No...they couldn't," Hanna whispered after a second. "We're the only ones who know. The four of us...and Alison."

The police question the girls—along with practically everybody from Rosewood, from Ali's second-grade gymnastics instructor to the guy who'd once sold her Marlboros at Wawa. It was the summer before eighth grade and the girls were supposed to be flirting with older boys at pool parties, eating corn on the cob in one another's backyard, and shopping all day at the King James Mall. Instead they were crying alone in their canopied beds or staring blankly at their photo-covered walls. Spencer went on a room-cleaning binge, reviewing what her fight with Ali had really been about, and thinking of things she knew about Ali that none of the others did. Hanna spent hours on her bedroom floor, hiding emptied Cheetos bags under her mattress. Emily couldn't stop obsessing over a letter she'd sent to Ali before she disappeared. Had Ali ever gotten it? Aria sat at her desk with Pigtunia. Slowly, the girls began calling one another less frequently. The same thoughts haunted all four of them, but there wasn't anything left to say to one another.

The summer turned into the school year, which turned into the next summer. Still no Ali. The police continued to search—but quietly. The media lost interest, heading off to obsess over a Center City triple homicide. Even the DiLaurentises moved out of Rosewood almost two and a half years after Alison disappeared. As for Spencer, Aria, Emily, and Hanna, something shifted in them, too. Now if they passed Ali's old street and glanced at her house, they didn't go into insta-cry mode. Instead, they started to feel something else.

Relief.

Sure, Alison was Alison. She was the shoulder to cry on, the only one you'd ever want calling up your crush to find out how he felt about you, and the final word on whether your new jeans made your butt look big. But the girls were also afraid of her. Ali knew more about them than anyone else did, including the bad stuff they wanted to bury—just like a body. It was horrible to think Ali might be dead, but...if she was, at least their secrets were safe.

And they were. For three years, anyway.