One of the biggest is, why did she direct the Liars to Maya's (Bianca Lawson) secret website? It seems like a very helpful thing to do for someone who is supposedly working against our heroes. So what gives?
Here are six theories about why Mona gave the website to the Liars.
1. She thought it would help frame Paige. It's possible Mona thought the information on the website was vague enough that the Liars wouldn't realize the killer was Nate (Sterling Sulieman). If that's the case, it's possible she thought Maya's cryptic messages, along with the other seeds the "A" team planted, would help incriminate Paige (Lindsey Shaw) in the Liars's minds.
2. She needed help hacking it. Given the "A" team's proven technical prowess, this seems unlikely. But it's possible the "A" team couldn't get into the site themselves, and thought they could trick the Liars into helping them.
3. It's misleading. It's possible that Mona thinks all of Maya's hints about knowing something and being in trouble will lead the Liars down the wrong path in some way that is useful for the "A" team.
4. To hurt Emily. Maybe Mona thinks seeing Maya's videos will just plain cause Emily more pain. We know she has a sadistic streak.
5. To help the Liars as part of an "A" plan. As we've seen in the past, sometimes "A" "helps" the Liars in various ways, though that help is always part of a grand scheme. Maybe that's the case here. Perhaps there is something about Maya the "A" team wants the Liars to figure out.
6. To help the Liars … not as part of an "A" plan. Or maybe Mona was acting as an independent agent. It's possible she's starting to regret what she did, or disagrees with the direction the "A" team is taking now that she's locked up. While she seemed to be totally on board with the team plan in Season 3, Episode 12: “The Lady Killer,” it's possible that she actually has her own plan in the works.
Why do you think Mona did it? Let us know in the comments below. Catch the PLL Halloween special on Tuesday, October 23 at 8 p.m. ET/PT onABC Family.
Rebecca Martin is an editor at Wetpaint Entertainment. Follow her on Twitter@BeccaMartin47.