Twenty: No Secrets Between Friends.

Thursday afternoon, Hanna stared at her reflection in the downstairs powder room mirror. She dabbed a bit of foundation on the stitches in her chin and winced. Why did stitches have to hurt so much? And why did Dr. Geist have to sew up her face with Frankenstein black thread? Couldn't he have used nice flesh-tone color?

She picked up her brand-new BlackBerry, considering. The phone had been waiting for her on the kitchen island when her father brought her home from the hospital earlier today. There was a card on the BlackBerry's box that said, Welcome Home! Love Mom. Now that Hanna wasn't on the brink of death, her mother had returned to her round-the-clock hours at work, business as usual.

Hanna sighed, then dialed the number on the back of her foundation bottle. "Hello, Bobbi Brown hotline!" a cheerful voice on the other end chirped.

"This is Hanna Marin," Hanna said briskly, trying to channel her inner Anna Wintour. "Can I book Bobbi for a makeup job?"

The hotline girl paused. "You'd have to go through Bobbi's booking agent for something like that. But I think she's really busy—"

"Can you get me her agent's number anyway?"

"I don't think I'm allowed to—"

"Sure you can," Hanna cooed. "I won't tell."

After a bit of hemming and hawing, the girl put Hanna on hold, and someone else picked up the line and gave Hanna a 212 phone number. She wrote it down in lipstick on the bathroom mirror and hung up, feeling ambivalent. On one hand, it rocked that she could still push people to do exactly what she wanted. Only queen-of-the-school divas could do that. On the other hand, what if even Bobbi couldn't fix Hanna's mess of a face?

The doorbell rang. Hanna dabbed more foundation on her stitches and headed into the hall. That was probably Mona, coming over to help audition male models for her party. She'd told Hanna she wanted to book her the best hotties money could buy.

Hanna paused in the foyer next to her mother's giant rake ceramic pot. What had Lucas meant at the hospital yesterday, when he said that Hanna shouldn't trust Mona? And more than that, what had that kiss been about? Hanna had thought of little else since it happened. Hanna had thought of little else since it happened. She'd expected to see Lucas at the hospital this morning, greeting her with magazines and a Starbucks latte. When he wasn't there, she'd felt…disappointed. And this afternoon, after her father dropped her off, Hanna had lingered on All My Children on TV for three whole minutes before changing the channel. Two characters on the soap were passionately kissing, and she'd watch them, wide-eyed, with tingles running up and down her back again, suddenly able to relate.

Not that she liked Lucas or anything. He wasn't in her stratosphere. And just to make sure, she'd asked Mona last night what she thought of Lucas, when Mona dropped off the coming-home-from-the-hospital outfit she'd selected from Hanna's closet—skinny Seven jeans, a cropped plaid Moschino jacket, and an ultra soft tee, Mona had said, "Lucas Beattie? Huge loser, Han. Always has been?"

So there you had it. No more Lucas. She would tell no one about the kiss, ever.

Hanna reached the front door, noticing the way Mona's white-blond hair glowed through the frosted panels. She nearly fell over when she opened the door and saw Spencer standing there behind Mona. And Emily and Aria were walking up the front path. Hanna wondered if she'd accidentally told all of them to visit at the same time.

"Well, this is a surprise," Hanna said nervously.

But it was Spencer who pushed around Mona and walked into Hanna's house first.

"We need to talk to you," she said. Mona, Emily, and Aria followed, and the girls assembled on Hanna's toffee-colored leather couches, sitting in the exact same seats they used to sit in when they used to be friends: Spencer in the big leather chair in the corner, and Emily and Aria on the couch. Mona had taken Ali's seat, on the chaise by the window. When Hanna squinted, she could almost mistake Mona for Ali. Hanna snuck a look to see if she was pissed, but Mona looked sort of…okay.

Hanna sat down on the leather chair's ottoman. "Um, we need to talk about what?" she asked Spencer. Aria and Emily looked a little confused too.

"We got another note from A after we left your hospital room," Spencer blurted.

"Spencer," Hanna hissed. Emily and Aria gaped at her too. Since when did they talk about A around other people?

"It's okay," Spencer said. "Mona knows. She's been getting notes from A too."

Hanna suddenly felt faint. She looked at Mona for confirmation, and Mona's mouth was taut and serious. "No," Hanna whispered.

"You?" Aria gasped.

"How many?" Emily stammered.

"Two," Mona admitted, staring at the outline of her knobby knees through her burnt orange C&C California jersey dress. "I got them this week. When I told Spencer about it yesterday, I never would have imagined that you guys were getting them too."

"But that doesn't make sense," Aria whispered, looking around at the others. "I thought A was only sending messages to Ali's old friends."

"Maybe everything we thought was wrong," Spencer said.

Hanna's stomach spun. "Did Spencer tell you about the SUV that hit me?"

"That it was A. And that you knew who A was." Mona's face was pale.

Spencer crossed her legs. "Anyway, we got a new note. A obviously doesn't want you to remember, Hanna. If we keep pushing you on it, A's going to hurt us next."

Emily let out a small whimper.

"This is really scary," Mona whispered. She hadn't stopped jiggling her foot, something she did only when she was very tense. "We should go to the police."

"Maybe we should," Emily agreed. "They could help us. This is serious."

"No!" Aria nearly shrieked. "A will know. It's like…A can see us, at all times."

Emily clamped her mouth shut, staring down at her hands.

Mona swallowed hard. "I guess I know what you mean, Aria. Ever since I've gotten the notes, I've felt like someone has been watching me." She looked around at them, her eyes wide and scared. "Who knows? A could be watching us right now."

Hanna shivered. Aria looked around frantically, canvassing Hanna's stuffy living room. Emily peeked behind Hanna's baby grand piano, as if A might be crouching in the corner. Then Mona's Sidekick buzzed, and everyone let out startled little yelps. When Mona pulled it out, her face paled. "Oh my God. It's another one."

Everyone gathered around Mona's phone. Her newest message was a belated birthday e-card. Below the images of happy balloons and a frosted white cake that Mona would never eat in real life, the messages read,

Happy belated b-day, Mona! So when are you going to tell Hanna what you did? I say wait until AFTER she finally gives you your birthday present. You might lose the friendship, but at least you'll get to keep the gift! —A

Hanna's blood turned to ice. "What you did? What's A talking about?"

Mona's face went white. "Hanna…okay. We did get into a fight the night of my party. But it was just a little one. Honestly. We should just forget about it."

Hanna's heart thrummed as loud as a car engine. Her mouth instantly went dry.

"I didn't want to bring up the fight after your accident because I didn't think it mattered," Mona went on, her voice high-pitched and desperate. "I didn't want to upset you. And I felt terrible about us fighting last week, Hanna, especially when I thought I'd lost you forever. I just wanted to forget it. I wanted to make it up to you by throwing you this amazing party, but—"

A few aching seconds passed. The heat switched on, making them all jump. Spencer cleared her throat. "You guys shouldn't fight," she said gently. "A's just trying to distract you from figuring out who's sending these awful notes in the first place."

Mona shot Spencer a grateful look. Hanna lowered her shoulders, feeling all eyes on her. The last thing she wanted to do was talk about this with the others around. She wasn't sure she wanted to talk about it at all. "Spencer's right. This is what A does."

The girls fell into silence, staring at the square-shaped, paper Noguchi lamp that sat on the coffee table. Spencer grabbed Mona's hand and squeezed. Emily grabbed Hanna's.

"What else have your notes been about?" Aria asked Mona quietly.

Mona ducked her head. "Just some stuff from the past."

Hanna bristled, focusing on the bluebird-shaped hair clip in Aria's hair. She had a feeling she knew just what A was taunting Mona about—the time before Hanna and Mona were friends, when Mona was dorky and uncool. What secret had A focused on most? When Mona had tagged along behind Ali, wanting to be just like her? When Mona was the butt of everyone's jokes? She and Mona never discussed the past, but sometimes Hanna felt like the painful memories loomed close behind, bubbling just below the surface of their friendship like an underground geyser.

"You don't have to tell us if you don't want to," Hanna said quickly. "A lot of our A notes have been about the past, too. There's lots of stuff we all want to forget."

She met her best friend's eyes, hoping Mona understood. Mona squeezed Hanna's hand. Hanna noticed that Mona was wearing the silver-and-turquoise ring Hanna had made for her in Jewelry II, even though it looked more like one of the clunky Rosewood Day class rings that only nerds wore than a pretty bauble from Tiffany. A small spot in Hanna's pounding heart warmed. A was right about one thing: Best friends shared everything. And how she and Mona could too.

The doorbell rang, three short Asian-inspired bongs. The girls shot up. "Who's that?" Aria whispered fearfully.

Mona stood, shaking out her long blond hair. She broke into a big smile ad pranced toward Hanna's front door. "Something to make us forget about our problems."

"What, like pizza?" Emily asked.

"No, ten male models from the Philly branches of the Wilhelmina modeling agency, of course," Mona said simply.

As if it were preposterous to think it could be anyone else.