One year after the mysterious disappearance of Alison Dilaurentis, Aria and her family return from Iceland. Spencer kisses her sister's boyfriend, Wren. Hanna is arrested for shoplifting a pair of sunglasses. Emily meets a fun girl named Maya.
Aria has an unsettling encounter with her father's former mistress, Meredith; Emily is forced to see Toby in a new light; Spencer is reeling in the wake of a vengeful Melissa; Hanna is desperate to Sean, forget the "old" Hanna; Detective Wilden uses his new connection to Hanna and Ashley to his benefit.
Tired of being harassed by "A," the girls decide to put a stop to the anonymous emails and text messages by blocking all unknown users. But the girls' problems are far from over with a surprise visit by a father, a surprise gift from a prospective paramour, getting some unwanted advice and an undeserved scholarly accolade.
Trying to ignore "A" backfires for the girls, and now they must pay the penalty. Whether it's a family in crisis, parental praise for an undeserved honor or wearing totally unfashionable scrubs while working off a debt; "A's" lipstick message is still haunting them; A new boy arrives and pushes the status quo, a secret love is tested, a new romance blooms and an old romance is floating in the grey area.
In the aftermath of the disastrous homecoming dance, the girls try to sort out the devastation that is left behind; The girls are sitting on some killer information about Toby that some people would die to get their hands on; "A" isn't the only one sending Aria text messages as tensions rise in the Montgomery household.
After much planning, the day of Alison's memorial is around the corner and the girls are ready to say their goodbyes; Alison's brother Jason arrives, and saying goodbye is at the bottom of his list. As Jason takes over, and Detective Wilden returns, will the girls be able to celebrate Alison's life in the peaceful and positive way they were hoping for?
A day of SAT testing is put on hold when a violent storm hits Rosewood; Each girl finds herself in the middle of a tense situation; Byron leans on Ashley for advice on parenting as his relationship with Ella takes a turn for the worse.
A new piece of evidence about Alison's disappearance brings the FBI to town, the last thing the girls want to do is go "glamping" for Mona's birthday. But when "A" sends the girls a text that they'll be at the party, Spencer thinks it will be their chance to finally put an end to the threats.
Moments after Hanna is hit by a car, the girls' world is turned upside down. "A" is no longer content playing a game of cat and mouse; With Hanna in the hospital and armed with the information of who "A" is, the girls are backtracking to figure out how they got to this point.
Hanna's return home from the hospital and is stuck in a wheelchair and feels haunted by "A"; Spencer is still reeling from Melissa's surprise; Emily is hoping that an introduction to Maya during a tense family meal will smooth all apprehensions her parents may have; Aria and Fitz suspect a student is on to them.
As Noel steps up his pursuit of Ezra, him and Aria start to feel like there may be no way out; Pam's perceived tolerance of Maya comes to a screeching halt; Spencer must handle the return of happy newlyweds Melissa and Ian; "A" has Hanna jumping through old habit hoops with regard to the stolen money.
As the school gets ready for the dance-a-thon, the girls have more on their minds; Hanna is having a hard time finding a job to help her family's financial situation, but when "A" has a job for her, will Hanna be able to refuse? Emily can only think of Maya and is desperate to speak to her; Spencer finds being in close quarters with Ian, more difficult than ever; Aria's former babysitter, Simone, comes back to town for a surprise visit, and soon sets her sights on Ezra.
Emily must deal with a jealous teammate who is threatened by Emily's return to the pool; Aria and Ezra plan their first date out in the open; Hanna is still stuck playing "A's" game; Spencer turns to Jason for information about the night they believe Alison died, only to have to face part of her unpleasant past with Ali.
Emily and Paige go for round two, as they are pitted against each other to compete for the anchor leg of the big race; Caleb calls in his favor with a guilty Hanna as she tries to deter Aria from asking too many questions about Ella's ticket to the museum opening; Spencer takes on the task of tutoring a fellow student to try and get some answers.
As the heat is turned up on the suspicions surrounding Spencer, the girls must come to the reality that they aren't the only ones hiding secrets in Rosewood. Spencer remembers something that happened the night of the murder.
Everyone has something to hide, but having to live with those secrets can become a big burden for the liars; Spencer and Toby aren't able to be seen together; Rosewood police officer Garrett keeps his promise to keep a close eye on the girls - much closer than they realize.