And here we go, chapter two! Thanks to HKcookie, Jmcncrlsd, and Quindecim for reviewing. I appreciate the feedback! This is a big chapter, and also where all of the similarities to the show's storyline end. From here on out, this is officially an AU. Like I said, reviews give me motivation, so the next chapter will be up either when I get seven or eight reviews, or by the end of next week. I hope you enjoy!

Chapter 2

"This is 'A's' lair."

It was not at all what Spencer was expecting. "A" always seemed so flashy, so big and bold, so advanced…she had expected some sort of technology, maybe, or at least something a little bigger than Room Two at the Lost Woods Resort.

But what she had just stepped into was…dingy. It was dark and dank and filled with creepy photos of her and the others, but mostly of Alison. It looked like the sort of thing that a teenager would have thrown together, not an evil mastermind.

And somewhere in this room, Spencer knew, was proof of her biggest secret. Forget her meaningless little affairs with Ian and Wren, and the truth about the Jenna Thing.

"A" knew that she killed Alison. And Spencer had been growing more desperate, ever since she got that cryptic message, to make sure they never got the opportunity to tell anyone.

"We need to look through everything. Search for anything that might tell us anything about what happened to Ali," she said to Mona, using that explanation as a cover for why she really wanted to take a look around.

Spencer knelt down beside a pile of boxes and grabbed one, ripping it open and digging through. Inside were photographs. Hundreds of them, all piled neatly in stacks, each with a date written carefully on the back.

Pictures of Aria, in the middle of an intense lip-lock with Ezra Fitz. Pictures of Emily, standing at the scene of Alison's destroyed memorial. Pictures of a police report detailing Hanna as a shoplifter.

And pictures of Spencer, kissing Wren, talking to Ian, confronting Melissa…

But none showing her striking Alison over the head with a shovel.

Spencer shoved the box aside and grabbed eagerly for another. She suddenly didn't care what other dirt "A" had on her. All she needed was to erase any evidence of what she had done that horrible night. And if "A" wanted to continue their reign of terror after that, Spencer realized, she didn't even mind. Because it suddenly occurred to her that if they all stopped lying, "A" would have nothing to hold over their heads.

And Spencer swore to herself, in that moment, that as long as she could destroy any evidence that could place her as Ali's murderer, she would never keep another secret again.

"Spencer?" Mona called from across the room, and she jumped, having forgotten that she wasn't alone. "This has to be 'A's' costume."

"What?" It took Spencer a moment to remember what they were actually here for. Still lost in thought, she stood up, adjusted the heavy ball gown that she was still wearing, and crossed the room.

"I'll call Hanna," Mona said, handing a small stack of papers to Spencer and pulling out her phone.

Spencer stared down at the drawings. A puffy black dress covered in feathers. A matching mask. " 'A's' dressed as the black swan," she muttered, relief coursing through her. If "A" was at the masquerade, that bought her more time. Time to make sure she found what she needed.

Mona was standing behind Spencer, gazing around the room, and pulled a pack of gum out of her purse, holding it out. "Gum?"

What? That was the farthest thing from Spencer's mind. "Um, no thanks," she mumbled, letting her arm holding the papers with the dress designs fall to her side as she walked over to an old wooden desk, picking up the little black and white journal that sat on it.

She had seen that journal before, she was sure of it, but she couldn't put her finger on where until she began flipping through it. The loopy, curly handwriting was unmistakable, handwriting she hadn't seen in over a year. "This is Ali's diary," she said, mostly to herself, just as she realized where she'd seen that black swan costume before. "Melissa was the black swan at a charity ball in Philly last year."

The thought that her sister could be "A" was somewhat concerning, Spencer had to admit. But then again…would Melissa really want Spencer thrown in jail? Would her own sister threaten her like that?

Spencer stared down at the journal in her hands. Ali had brought that thing practically everywhere with her, was always leaning over it and shielding it with her hand whenever anyone tried to sneak a peek. She could only imagine what Ali had written in there…about her.

Maybe even enough to tell that she and Alison hadn't exactly been on the best of terms leading up to the night that Ali ended up buried underneath the gazebo construction.

"You don't think she'd do anything to try and hurt you, do you?" Mona was saying, flipping through the black swan designs, but her voice sounded far away.

Spencer shook her head, dazed, her mind still focused on Alison. "Why would you ask me that?" she asked, horrified. Sure, Ali had been kind of a huge bitch to Spencer before her death, but she wouldn't have actually –

"Well, I just thought that's what you meant. Melissa's the black swan. Maybe she's 'A.'"

Oh. Melissa. Right. Spencer frowned, not taking her eyes off of the journal. Suddenly, her head felt like it was going to explode. Reaching a hand up to rub her temple, she said, "Actually, can I have that gum now?"

"Sure," Mona chirped, but frowned once she pulled out the empty pack. "Oh. You know, I think I have more in the car, so I'll be right back, okay?"

"Yeah," Spencer murmured, glad for the opportunity to be alone. She needed to look through that diary, to find out just how much of Spencer and Alison's relationship "A" knew, and she didn't need Mona asking a bunch of questions.

She kneeled down, weighing the journal in her hands, and it fell open to a page marked with a gum wrapper. Her eyes scanned over the writing – some vague story about a girl nicknamed "Pigskin," apparently – before she focused on the wrapper.

Gum. Wait a minute.

Spencer set down the journal, memories of "That Night" temporarily forgotten. Her eyes landed on a shopping bag, stuffed with tissue paper, and she reached out for it, digging beneath the paper and pulling out a piece of clothing.

"Cashmere sweaters," she whispered, turning the bag over in her hands and recognizing the name on the sticker as a store in Philly. A cold feeling washed over her.

"I got the gum," Mona said from the doorway, her voice suddenly sharp, just as Spencer put the pieces together.

"You didn't call Hanna, did you?" she asked quietly, rising to her feet and turning to stare at the smaller girl, who had exchanged her dress for the black hoodie that Spencer had been expecting, but was still surprised to see.

This was all a trap, she realized, and her next words fell from her mouth before she was even conscious of thinking them. "Because you're 'A.'"

"Congratulations, Spencer," Mona snapped, looking like a completely different person with the black hood pulled around her face. "You figured it out."

Spencer could barely breathe. And in the next moment, pain exploded in her head, and everything went black.

…

She woke to the sound of a car bumping along gravel, and opened her eyes slowly, realizing all at once what was going on.

She had just unmasked "A."

Mona was "A." And she knew Spencer's deepest secret.

She groaned in pain and turned her head, sitting up. Mona was beside her, in the driver's seat, steering the car up the steep, sloping cliff toward Lookout Point at a dangerously fast speed.

"What's going on?" Spencer asked, feeling her heart pounding wildly in her chest. There was nothing up at Lookout Point except for the fifty foot high cliff side. There would be no reason to go there unless…unless someone wasn't going to come back down. "What are you doing?"

"I had to get you alone, so we could talk," Mona replied, her voice strangely monotone. Spencer could hardly believe it. Out of all of their suspects over the past months, everyone who had made a vague threat or acted suspicious…

This was almost funny. She would have laughed, had she not felt paralyzed with terror. "Okay," she said slowly, shifting and feeling something small and hard digging into her side…her phone. "So let's talk," she stalled, slowly reaching her hand down to pull her cell phone out of the pocket of her jacket. Once she had it safely in her lap, she glanced down at it, just in time to see Aria's name pop up as a new call came in.

"I admire you, Spencer," Mona said, turning the wheel sharply as the car shot around a curve. Spencer's stomach flipped. "I want to make you an offer. We can be in this together."

"You're asking me to be 'A' with you?" Spencer asked, her voice trembling and finally cracking. Her finger covered over the "video call" button. "And what if I say no?"

"Then you'll be wearing an orange jumpsuit instead of a black hoodie." Mona smiled and suddenly slammed on the brakes. The car jerked to a stop, in the middle of the road, and Spencer lurched forward, her hands shooting out to stop her inches before her face connected with the dashboard.

"What?" she gasped, pressing a hand to her chest. She felt lightheaded, like this couldn't be real, it was all some horrible dream…

"What, you thought that text I sent you was just a joke?" Mona snapped, turning to look at her, and Spencer forced down the urge to respond with a sarcastic "which one?"

She knew exactly which one. It was the only one, out of so many threatening "A" messages and texts, that she had looked at enough to burn to her memory.

"How do you know?" she choked out, her throat suddenly dry. She glanced to her right, at the door handle. All she had to do was wait for the right opportunity, and she could…

As if reading her thoughts, Mona flipped a switch on the dash, and every door locked with a simultaneous click. Spencer felt her heart sink, and even more so when the smaller girl spoke. "I saw you hit Alison that night," she said almost triumphantly, pulling out what looked to be a burner phone and fiddling with it for a moment. "And I have proof."

Then she held the phone out for Spencer to see the video that was beginning to play. It was somewhat bad quality, obviously taken from behind a bush or tree, and the sound was dim, but there was no mistaking the two girls that stood facing each other in clear view of the camera, one in a yellow tank top, the other in an argyle sweater.

"Oh my God," Alison's familiar, shocked voice came through the phone's speakers, and Spencer leaned back against the seat, trying to push herself as far away as possible from that horrible video, that horrible memory. "I can't believe it. You're speeding."

Spencer watched the younger version of herself, looking dazed, reach for the shovel. She closed her eyes. She didn't need to see what happened next – she already knew.

But even so, Mona didn't stop the video, and Spencer heard the dull thump of the shovel connecting with Ali's skull all too clearly. Her vision spun behind her closed eyelids. She was sure that she was going to puke.

"How did you see that?" she finally asked, taking in a deep breath and opening her eyes only once she was sure that the video had ended. "How did you see everything?"

"You're not the only genius in this car, Spencer," Mona snapped, and even through her own agony, Spencer detected the bitterness in her tone. "And now you're going to make a choice. Either you join the team, or 'A' sends that video straight to the police."

Spencer couldn't think straight. She glanced down, looking around wildly for her phone, only to spot it laying on the floor of the car, the screen shattered. It must have fallen when the car had jolted to a stop.

She was alone with "A." Her friends had no idea where she was, and there was no way she could get out of this car without making a choice.

Either join the "A" team and betray her friends, or be convicted of Alison's murder, after all this time.

She and the others had been tormented by "A" for months. Their lives had been made miserable by this single tormentor, someone so omnipresent and willing to expose their deepest secrets. They had all lived in fear, through it all – the homecoming disaster, Hanna's accident, Ian's murder…could Spencer really actively participate in something so horrible, just to save her own skin?

The answer suddenly stuck out to her, so obvious that the words appeared on the tip of her tongue.

Spencer took in a deep breath and turned in her seat, meeting Mona's eyes. "You don't have to say any more," she said, her voice surprisingly steady. "I'm in."