For Torrey DeVitto, playing super-sketchy Melissa Hastings on Pretty Little Liars wasn’t exactly a challenge. Because, despite the seemingly endless web of lies surrounding the eldest Hastings sister on the show, it all looks like child’s play compared to DeVitto’s other unforgettable role as psychotic Nanny Carrie on One Tree Hill. And really, in the world of TV villains, nothing could ever top portraying an axe-wielding ex-babysitter who stalked her former charge through a cornfield.

Luckily, DeVitto has fully embraced playing the villain at this point. “It’s so much fun,” she recently said when she stopped by InStyle’s New York City HQ. “I love it much more than playing the nice love interest or something boring. You get to take out all of your aggression and do things that you’d never do in real life. It’s great.”

Credit: Richard Shotwell/Invision/AP

While she’s certainly played one of Pretty Little Liars’ more suspect characters, the jury is still out when it comes to the identity of the Freeform series’ uber-villain, A.D.—and Melissa’s not out of the running (at least in our minds) just yet. Of course, DeVitto isn’t about to give away any spoilers. “I can’t say anything,” she said. “They’re so tight-lipped about everything.”

She may not be able to dish on the finale, but DeVitto’s character was full of surprises right up until the end. “I always felt like I’d get a grasp on her, and then I’d read a new script, and think, ‘Oh, she is totally different than I thought,’” said DeVitto. “This is the only character that I’ve played for so long that I still feel like I did not know. She changed all the time, and I couldn’t always keep up. Once I’d get new information, I’d be like, ‘Shouldn’t I have done that last episode totally different?’”

Credit: Adam Taylor/ABC

With the series finale airing next week, DeVitto—who also stars on Chicago Med—was more than ready to wrap up her character’s storyline and put our long-held suspicions to rest. And while she can’t reveal what’s in store for Melissa—as well as the rest of the Liars—she promises that the episode will pack one last dose of juicy drama. “When the script came, it was extremely thick,” said DeVitto. “My coworkers on Chicago Med saw it sitting on my chair, and they were like, “What is that? Is that a bible?’”

After reading the script, DeVitto believes fans will finally get closure about some of Rosewood’s biggest mysteries to date. “I think people are going to be so pleasantly surprised,” she said. “It definitely answers all the questions, and I’m very happy with it. It’s very satisfying.” The ending may be satisfying, but is it what she expected? “I haven’t seen a fan theory yet that’s hit it on the head,” said DeVitto. “I’ll just say that.”