Get ready Pretty Little Liars fans because tonight’s episode (Season 3, Episode 19: “What Becomes of the Broken-Hearted?”) marks a major confrontation between Spencer (Troian Bellisario) and Mona.

To get the juicy scoop on the PLL “catfight,” Wetpaint Entertainment chatted with Janel Parrish about Spence and Mona’s “cat-and-mouse game” and tonight’s “intense” episode.

Wetpaint Entertainment: What’s coming up for Mona and Spencer?

Janel Parrish: Well, Spencer now knows that Mona and Toby are working together. Mona is not fooling Spencer for one second. So, as you know, they're on this academic decathlon team now. So that means they're going to be spending a lot more time together. It's going to be kind of a cat-and-mouse game for the next episode. Mona's still playing, “I don't know what you're talking about. I'm super sweet now,” and Spencer's just on to her. So there might be just a little catfight coming up.

Really?

We do love catfights. It's not the first time Mona and Spencer had a catfight. The last time that happened is when Spencer and Mona tackled each other and Mona fell off of the cliff. So it won't be something as intense as that, but it is definitely going to be something. Also, Dr. Sullivan’s (Annabeth Gish) coming back to town to help Emily (Shay Mitchell) deal with her trauma of killing Nate. So when that happens, Emily kind of digs up some other memories that she didn't know she had about Alison's death. It will be intense, for sure.

And Mona and Dr. Sullivan have a run‑in, right?

Yes. Mona definitely goes to visit Dr. Sullivan. It will be a very interesting exchange between the two of them.

Why does Mona feel the need to see her?
 
Oh, you know, Mona shows up with a flower, and is basically just like, “Oh, hey. I just want you to know that I'm better. I'm great, and thank you for everything.” The scene is about finding out whether Dr. Sullivan really believes Mona or not.

Hmm.
 
It sounds like you don't believe Mona for one second.

I don't believe Mona for one second, but I kind of love the fact that they let Mona and Toby be as crazy as they are, and we know that. As opposed to having us try to figure it out.
 
That's true. They're not trying to hide anything. Like this girl's crazy, but it's really fun to watch her try to be all these different personalities.

Let's be honest: You love that crazy b****.

I've got to say, I love the crazy b****. I love the crazy Mona bitch, or the Mona monster as Caleb called her once. It's so much fun, and I can't lie, I'm really excited to go back for Season 4 and see what other tricks she has up her sleeve. She always does. You know that.

What's it like for you and Troian? The catfight stuff sounds pretty fun?

Oh my god. We love it. We have so much fun with it. I mean, Mona and Spencer, if anything, those two characters are the characters that are the most alike when it comes to how clever they are and how smart they are. So I think Mona really enjoys that kind of banter she has with Spencer because she likes to bait Spencer, and she knows that if any of the girls are smart enough to play Mona's game, it's Spencer. So, I think, those scenes are always fun for Troian and I to play because we have a good time just kind of playing with the scene and seeing where it goes. Troian has no fear. She's not afraid to just go there. We like to play.

When Spencer finally snaps, is it within a school environment or will they actually take this outside of school?

It will be an environment where Spencer will be really embarrassed that she snapped.

Catch the next episode of Pretty Little Liars on Tuesday, February 5, 2013 at 8 p.m. ET/PT on ABC Family.