Title: Transgressions

Summary: Mona has a visit from an old friend after she defects to the liars' side.

Disclaimer: I don't own PLL or anything related to the show.

Rating: T

A/N: One-shot, set early series 4 and a little darker than my usual Paily fics.


Mona Vanderwaal was used to skulking in the shadows of Rosewood's main street. She had spent most of her teenage years lurking unseen in the background, silently watching Allison Dilaurentis and her little minions. It hadn't been hard to learn their secrets. Allison and the others had always overlooked Mona; they had overlooked a lot of people. When Allison had disappeared it had opened up the spotlight for people like Mona to step in to it, but even when she had been standing soaking up the limelight, Mona had always had one foot firmly in the darkness; and she wasn't the only one.

She stopped in the middle of the street, smiling to herself as she caught the sound of footsteps behind her. She knew all too well that if she turned around the street behind her would be empty, it was almost midnight after all. Mona assessed her options in the blink of an eye. She took in the all night diner on the corner of the street, lit up like a Christmas tree in the dark, and the alleyway to her left that led to a dead end. She chose to turn left, knowing her pursuer would wait half a beat to follow her down it.

She was leaning casually against a fire escape as Paige McCullers rounded the corner. Her cheeks were flushed from the cold, yet her skin looked pale against the black hoodie she was wearing. It was an interesting choice of attire; and a deliberate one.

"Hello Paige. A little late for a walk, isn't it?" Mona Wanderwaal could be classed as many things, including a high functioning sociopath. As such, she rarely felt any kind of fear. There was a tingle of something close running along her spine though, as Paige pushed her hood back and crossed her arms over her chest, staring the other girl down.
"We need to talk." Her voice was as cold and flat as her expression. For a second, she almost looked like the old Paige; the cold blooded shark who, not so long ago, Mona had found a kindred spirit in.

"Are you afraid I'm going to spill some of your secrets?" Mona teased, trying to keep her cool as Paige started circling her. Few people intimidated her, but anyone who could stand up to Allison Diluarentis had to be handled carefully. There had been a time when they had been on the same side, but the lines had started to blur once they'd lost their common enemy.

"I don't know what game you're playing here Mona, but I don't trust you." Paige didn't mince her words as she rounded on the smaller girl. "And neither does Emily, or any of the others; not even Hanna. Not really."

Paige was trying to push her buttons, but she had just hit a big red button that should have been left untouched. Hanna was off limits. Paige knew that. "Like they trust you?" A slow smile spread over Mona's lips as she wrestled back control. "What would they think if they knew what part you played in the A team-" Her threat died in her throat as Paige shot forward, clamping a hand around her neck and pushing her back up against the wall.

Mona hadn't created 'A' on her own. The shadowy entity had been born from Paige and Mona's equal hatred of Allison Dilaurentis. "When we started this thing it was all about giving Allison what she deserved! Those girls didn't deserve any of what you put them through!" Paige growled, her hot temper bubbling up to the surface. She had slipped out of the house in order to confront Mona, to make sure she had really given up on terrorising Emily and her friends; but part of her had needed to get a message across to Rosewood's resident psycho, to make it crystal clear that she needed to keep her mouth shut.

Where Mona had revelled in the darkness, Paige had clawed her way back out of it. She was not the same person who had conspired to take Allison down one text at a time. She was different now; or at least that's what she kept telling herself. It was a little harder to believe it while she had one hand wrapped around Mona's throat.

"I gave you some slack because of what Allison put you through. What she put us both through; but don't think for one second that I will ever let you hurt Emily again! Go near her and I will bury you!" Paige warned the other girl, her voice coming out in a thick growl. Despite the evident fear in her eyes, and the fact that Paige's hand was still clamped tightly around her windpipe, Mona managed a condescending chuckle.
"You might want to do a better job of it than you did with Allison; that bitch just won't stay in her grave will she?"

"What?" Paige took a step back, finally letting go of the other girl's throat. Her eyes were wide with indignation as she took in what Mona had just accused her of. "I didn't have anything to do with what happened to her!"
"Right. Of course you didn't." Mona rolled her eyes at her former friend. The teenage sociopath seemed to be finding her footing again as she went on the offensive. "The two people who hated Allison most in the world are standing right here; and I know I sure as hell didn't kill her. So that leaves you, Pigskin."

"Don't call me that!" Paige snapped, red hot anger taking over her as the unflattering nickname brought back a flood of painful memories. "I defended you! The only reason Allison even started with me was because I stood up to her when she was beating on you!" There had been a time, long before Emily had even known that Paige existed, when Paige and Mona had been friends. That suddenly seemed like a lifetime ago as the two girls stood staring each other down.

For all of Mona's many faults, there was still a part of Paige that looked at her and saw only another one of Allison's victims. Mona picked up on that weakness in an instant and tried to twist it to her advantage. "You were my best friend Paige...my only friend. And okay, I took things a little too far going after the others, but I'm not the big player in town any more. There's another A out there and they're after Emily and her friends...We can work together and-"

"No." Paige cut her off with an almost violent shake of her head. "I don't need your help protecting my girlfriend! Just stay the hell away from me, and from Emily! I would warn you to stay away from Hanna too, but I think she's already made it pretty clear that she wants nothing to do with you!" Paige sneered as she delivered the cruel parting blow; knowing just how deep it would cut the other girl.

Mona tried not to let her pain show through as she forced a sickly sweet smile on to her perfectly glossed lips. "Don't say I didn't give you a chance McCullers. This new A is a total bad ass; and you and Allison's little minions are going to need all the friends you can get. So I wouldn't cast me out in to the cold just yet... not when A's gunning for your girl." Only Mona could make an offer of friendship and a threat in the same breath.

Paige wasn't fazed by the smaller girl, though Mona was right about the new A being an even bigger threat. She seemed to forget who she was talking to though. Paige McCullers didn't scare easily. There was nothing that A could do to her that could be worse than what she'd done to herself during some of her darker days.

Emily had been her saving light. She had picked Paige up out of that darkness; there was nothing that Paige wouldn't do for the girl she loved so deeply. She had fought tooth and nail to be with Emily; to prove to herself and everyone else that she deserved her. That she deserved the second chance she had been given. She stood her ground at the end of the alley, her gaze burning in to Mona's as she stared the other girl down, waiting for her to blink. A slow smile spread over her lips as Mona looked away first.

"So let the bitch come."