We've taken a close look at the sneak peeks of the episode to see what we can learn about it before it airs tonight.
1. Spencer doesn't tell the Liars about Toby. In the sneak peek below, Spencer (Troian Bellisario) lives up to the name of the show, lying to her friends about what went down during her anniversary "celebration" with Toby (Keegan Allen).
2. Hanna is worried about Caleb. In the same promo, Hanna (Ashley Benson) notes that Caleb (Tyler Blackburn) is "being really weird," claiming he's busy all the time but not filling her in on his plans.
4. Should they turn the key into the cops? In this clip, Emily (Shay Mitchell) still seems interested in turning the "A" key into the cops, which Aria thinks is a terrible idea.
5. A huge clue. In the same clip, the Liars discover an old, written conversation between Alison (Sasha Pieterse) and a mysterious second person. Ali and her friend talked about an unnamed "beach hottie," and (dun, dun, dun) Toby.
6. Emily plays detective. In this sneak peek Emily seems determined to track down the meaning of the clue. We love seeing her on the warpath.
7. Spencer flips. Meanwhile, based on the same clip it looks like we're in for a lot of emotional Spencer time this week. Yes, please!
For more on the episode, see what we can deduce from the preview here.
Catch the episode tonight, January 29, 2013 at 8 p.m. ET/PT on ABC Family.
Rebecca Martin is an editor at Wetpaint Entertainment. Follow her on Twitter @BeccaDMartin.