By Tanner Stransky
January 08, 2013 at 02:13 PM EST
Andrew Eccles/ABC Family

ABC Family’s addictive hit drama Pretty Little Liars returns at 8 p.m. tonight to finish the second half of its third season. As always, there’s a bevy of gnarly twists and turns to come — especially in tonight’s installment titled “She’s Better Now.” (There’s a big hint of what’s to come for you.)

We chronicled the coming season in our Winter TV Preview issue, which is available on newsstands now, but here are a few teases from the upcoming 11 episodes:

–Mona is back! You probably knew that, and you probably even saw our exclusive sneak peek at tonight’s season premiere over on our Facebook page (Like it for access to the clip if you haven’t!), but is Mona good… or still bad? “What does Mona’s return mean for Rosewood and the girls?” Whether she’ll still be secretly (or not so secretly?) terrorizing Aria (Lucy Hale), Hanna (Ashley Benson), Emily (Shay Mitchell), and Spencer (Troian Bellisario) remains to be seen, but executive producer Marlene King says her motives are still dark. “She’s a villain out walking amongst the PLLs,” she says. Adds executive producer Oliver Goldstick: “She’s not coming back as Polly Purebread.”

–Byron is going to look guilty! Garrett’s (Yani Gellman) mysterious death in the show’s October Halloween special — and his pre-murder revelation that Aria’s father, Byron (Chad Lowe), was the last to see Alison alive — will still have residents reeling. “You’re going to believe Byron killed Alison,” Goldstick says. “Byron had a very weird, off-the-wall relationship with Alison.” The details of that relationship will trickle out via diary pages that the girls snatch from a very unlikely source: the creepy manager of the Lost Woods Resort (Travis Richey), who is now, oddly, a janitor at Rosewood High. (Could he be helping Mona on the sly? Possibly.)

–Spencer will soon find out about Toby! She has what might be the biggest emotional wallop coming — Spencer will soon discover what viewers already know, that her beau, Toby (Keegan Allen), is part of the “A” team that has been threatening her and her friends over the past two seasons. “She’s decimated by the ultimate betrayal,” says Goldstick. Though Bellisario cautions, “Some people think that he’s not really bad — that he’s working to protect her.”

Tanner on Twitter: @EWTanStransky

Read more:

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‘Pretty Little Liars’ Halloween episode: Garrett returns with details about Alison’s death! — EXCLUSIVE VIDEO