A month has passed since the liars were arrested and they're at each others' throats and Emily has been iced out completely. But what could have divided them so severely, has "A" finally won the game of divide and conquer?

The liars, realizing that "A" is not acting alone and their helper may be closer than they think, decide to enlist Caleb's hacking skills.

With Lucas missing and questions surrounding what happened out on the lake, Hanna can barely catch her breath; Spencer follows a lead about "A" which guides her to an unexpected place and revelation.

Toby continues to pursue Spencer, knowing that she is keeping something from him; Hanna begs the other girls to stop using Caleb to help with their search; Aria is desperate to save her relationship with Ezra.

After speaking to her friends about Caleb, Hanna feels they are giving her the cold shoulder; Emily hopes to re-introduce Maya to her mother.

Aria continues to question Holden on what exactly he is up to during their "date nights"; Hanna tries to figure out the latest situation with Kate; Emily gets help from an unlikely source to get back on the Rosewood swim team.

Hanna's worst nightmare comes to fruition when Caleb becomes a target of "A" and his computer is in possession of the cops; Aria learns what Holden's been keeping a secret.

A surprising new victim of "A" is revealed; Spencer runs from her family troubles right into Wren's arms; Ezra's new opportunity could push him away from Aria.