The liars follow a lead about where Maya might have been before her murder; Aria must deal with the aftermath of meeting Ezra's mom.

Spencer learns about Paige's shocking past with Ali, but will Emily listen to what her friends have to say?; Aria feels she has to help Ezra move on from his past.

Emily is caught in the crossfire as Maya's murderer is revealed; The liars are betrayed by someone close to them.

Trick or treat? The Rosewood Halloween Ghost Train becomes one killer party in this special Halloween-themed episode. Plus, Adam Lambert performs.

Radley Sanitarium gives Mona a clean bill of health, and she heads back to Rosewood High, much to the liars' dismay.

Aria, Emily, Hanna and Spencer are sure that Mona is up to her old tricks again, but can they prove it? Meanwhile, Aria's fears about her father grow stronger.

Meredith helps take care of Aria when she is sick - but could she have ulterior motives?; Spencer surprises Toby for their anniversary.