Emily digs for answers about Mona and Ezra; Hanna learns about a possible new lead in Alison's case.
Aria learns about Ezra's betrayal; Spencer tries to prove that she can overcome her addiction.
The girls don't know what to believe when Spencer's addiction places her credibility into question.
Spencer's reality is transformed to that of a black-and-white, film-noir world.
Prescription medication and sleepless nights affect Spencer; Emily hopes to make amends with Alison.
Hanna tries to determine the identity of the body in Ali's grave; Aria dislikes Mike's new friend.
Shana returns to Ravenswood; the girls try to decide if new information about Ali is true.
The girls hope Ali's diary can shed light on their many questions.
Armed with the knowledge that Alison is alive, the Liars have more questions now than ever before.
The Liars crash the Ravenswood Founders Day Celebration during the annual Halloween special.
An intriguing riddle from "A" has the Liars hitting the road and heading to Ravenswood.
With "A" hiding out closer than realized, the Liars step up their investigation.
Ezra continues to reel from Maggie's big news when he's dealt an even more crushing blow regarding his son.
Paige throws Emily a surprise birthday party with even more surprising guests -- Jenna and Shana.
Aria relies on Jake to help her understand Mike's new attitude.