Caleb and Toby team up to investigate "A" and what happened the night of the lodge fire; Ezra struggles with how he fits into Aria's life; Hanna tries to act normal.

It is a rough time for all of the Liars as Spencer is reeling about the memories from her "lost summer," Aria is still nursing a broken heart, Emily is reeling from Paige's betrayal and Hanna unsuccessfully attempts to wade back into the dating pool. But as each girl tries to deal with her individual issues, they must focus their attention on their suspicions surrounding Mrs. DiLaurentis. Assuming that Mrs. D knows more about Ali and the night she went missing, girls decide to help out at her charity bridal fashion show to gain access to the DiLaurentis house to search for answers. Meanwhile, Ella and Jason return to Rosewood, each with something to hide.

Caleb tries to convince Hanna that Mona can't be trusted, causing Mona to prove her loyalty in the most unexpected way; Emily reconnects with her old boss Zoe.

The liars finally get answers about the night Ali disappeared. With their newfound knowledge of Ali's long-held secrets, can they figure out who "A" is?

Paige throws Emily a surprise birthday party; Mona's selfless act provides Hanna and her mother with their first bit of good news; Ezra gets some distressing news.

The PLLs must dodge their dreaded nemesis, "A," while navigating a world with Alison back in it.

Mrs. DiLaurentis offers to let Emily move into Ali's old room; Trying to get involved in Jake's interests; Aria finds an opportunity to follow a lead.

The liars try to wrap their head around the new normal; Jason's odd behavior and Kenneth's search for Jessica starts to raise eyebrows.

Ezra reaches out to Aria, just as she decides to move on with Jake; A Western-themed dance turns into a two-step with "A"; Hanna is stalked by a fellow student.

An intriguing riddle from "A" has the liars hitting the road and heading to Ravenswood, where they make a shocking discovery.

The liars are forced to live through Ali's latest lie; Hanna and Aria have loose ends with two people who know about Ali's story; Spencer and Emily try to uncover Jason's whereabouts in New York.

The liars crash the Ravenswood Founders Day Celebration after a clue suggests Ali may be alive; Caleb meets a kindred soul, Miranda.

The liars keep their distance from Ali; Spencer finds out Peter has a little more than something to do with Jessica's murder; Aria wants to know more about Shana.

Now it's confirmed that Alison is alive, who was buried in Ali's coffin?

Ali returns to Rosewood High and hopes to help heal the damage she did years ago, but not if Mona and her army have anything to say about it; Caleb and an old foe return to Rosewood.

After Hanna reveals that she has Ali's diary, the liars hope it can answer some questions, but are they ready to admit which personal story is about them?

With 'A' back in their lives, the girls are determined more than ever to know his/her identity. While Ali prepares to run away from Rosewood, Hanna faces a challenge in her relationships. Detective Tanner digs deeper into the death of Shana.

Shana says that Ali wants to meet Emily - and not the other girls - but could it all be part of an "A" plan?; Aria and Hanna deal with matters of the heart.