Emily's relationship with Paige has been anything but easy, but she finally feels like their relationship is going in the right direction. So when Spencer comes to her with a sordid tale about Paige's history with Alison, Emily is not ready to heed her friend's warnings. With Spencer knowing Paige's violent past and this new information about a blood feud between Alison and Paige right before Alison disappeared, she can't stand by to let one of her best friends get close to a potential enemy. But will Spencer cross a line that Emily can't forgive in her attempt to prove to Emily who Paige really is?

Meanwhile, Aria feels she has to help Ezra move on from his past if their relationship is to move forward, but what she finds may be more than she expected.

With Garrett's trial for Maya's murder starting, the town of Rosewood has become a media spectacle. At odds with her friends over Paige, Emily doesn't know where to turn when the media attention becomes too much for her. "A" sees this as a perfect opportunity and takes advantage of the situation and sends Aria, Emily, Hanna and Spencer on a path to a possible truce. But is "A's' peace offering real or just a trap for a much darker ending?

Meanwhile, Aria, Emily, Hanna and Spencer are betrayed as someone very close to them is revealed as part of the "A" team.

Spencer is finally ready to talk, but Emily is not so ready to accept what she has to say. Will she heed Spencer's warnings or will Emily go off to find her own answers down a path "A" has designed for her? Hanna, on the other hand, is preoccupied with helping her mother after Ashley is involved in a hit-n-run accident. Now having a new secret to hide, Hanna wonders if "A" had something to do with it after all. With Aria, Emily, Hanna and Spencer are now really afraid does "A" have them right where they want them? Meanwhile, Aria has to come to terms with Ezra's new life with Malcolm.

In the season four premiere, the Liars are desperate to uncover what new scheme "A" has in store for them in the wake of the lodge fire, and have no choice but to turn to Mona for answers, now that she is also being targeted. Aria struggles with seeing Ezra in the wake of their breakup, and Emily starts to make plans for life after high school. Meanwhile, "A" sets Toby on a new path, what's in the trunk is revealed, and a shocking discovery reverberates through Rosewood.

Paige throws Emily a surprise birthday party with even more surprising guests – Jenna and Shana. But it’s “A’s” actions at the party that lead to the biggest shock of all. Mona’s selfless act provides Hanna and her mother with their first bit of good news, but sends Mona down a familiar path. And Ezra gets some distressing news from Maggie regarding her and Malcolm. Meanwhile, Aria and Jake continue trying to define their confusing relationship. And Emily meets with a world class coach in a last ditch effort to salvage her swimming career.

Still living at a motel, Emily is taken aback when Mrs. Dilaurentis offers to let her move into Ali's old room and is even more distraught when the other Liars insist she take Mrs. D up on her offer. Hanna explodes when it appears her mother's recent good fortune has taken a turn for the worse. And Ezra continues to reel from Maggie's big news when he's dealt an even more crushing blow regarding his son. Meanwhile, Aria makes an effort to get involved in Jake's interests and finds herself with an opportunity to follow up on a lead. And "A" continues to toy with Toby's emotions regarding his mother's death, and Spencer is along for the ride.

Hanna's new interest in crime novels helps her to come up with a plan to try and figure out whose body is in Ali's grave. While Hanna is on her hunt, Spencer is working overtime to decipher the stories in Ali's diary which she hopes will reveal the identity of Ali's mystery man. But with both girls hot on the trail, will their work lead them straight into "A's" path? Meanwhile, Aria is upset with the new friend Mike has made and Emily's dad is concerned about her behavior.