Emily butts heads with teenager Addison, who appears to be a new version of high school Ali, and who may be connected to a familiar foe. Spencer confronts her mother about keeping family secrets. Aria confides in Holden about her relationship with Ezra, while Spencer turns to Detective Furey for help. And Jenna stirs up even more trouble when she returns to Rosewood with some insight into Noel Kahn and recent events.

Spencer focuses on learning more about her connection to Mary Drake, while Aria and Ezra figure out what their future may hold now that Nicole is back in the picture. Mona helps Hanna get her fashion career back on track, and Emily struggles to balance things between Ali and Paige now that the three of them are working at Rosewood High. Meanwhile, A.D. has a special delivery for the Liars, one that reveals the final endgame.

The Liars face off with their enemies in a chaotic fight that ends fatally. One of the PLLs learns a secret about her past that changes everything while another Liar discovers something about her future that could alter her course forever.

One of the PLLs goes rogue to prove that Noel Kahn is Uber A, while the others try to find evidence to back her theory and worry about her emotional state. Emily unexpectedly turns to Paige for comfort in her time of need, which causes tension in her other relationships. Jason and Aria team up to look into Mary’s past and what she might be hiding.

Emily goes up for a position as the Rosewood High swim coach, only to learn that her ex-girlfriend Paige is also up for the job. Hanna is visited by Mrs. Grunwald after she has a vision that the PLLs are in danger. The girls track down the doctor who delivered Mary’s baby in order to get answers. Ali decides to go back to work to help bring some normalcy to her life again.

Jason returns to town to stop Ali from getting too close to Mary. The girls learn something new about Mary and Mrs. DiLaurentis that leads them to a storm cellar full of clues. Ezra gets a call about someone in his past that could change his course. Noel Kahn grows more and more suspicious and rises to the top of the list of suspects for Uber A.

The Rosewood P.D. begins to unravel the Liars’ cover-up, which leads them to question Rollins’ death altogether. Hanna deals with an inward battle on whether or not to tell the cops the truth, while Ezria struggles with an awkwardness in their relationship. Jenna reveals part of her plot and a new partner she is in cahoots with. Ali learns that the Liars gave her up as Charlotte’s killer in order to free Hanna, which does not go over well. Meanwhile, someone is murdered for playing with the wrong team.

Jenna returns to Rosewood and befriends another one of the Liars’ enemies, making her the PLL’s number one suspect for Uber A. In order to leave the psychiatric hospital, Ali must be released into the care of a relative, leaving her under the suspicious watch of Mary Drake. Spencer enlists Hanna’s help to search for Caleb as he’s missing in action. Aria and Emily stumble upon a secret apartment they hope will lead them to more answers.

The PLLs desperately attempt to cover up their secret, and in turn, end up straining their relationships with their respective bed buddies by keeping them in the dark. While the aftermath of Haleb’s kiss weighs on Spaleb’s relationship, Spencer copes in ways she might later regret. Mona intervenes with the cover-up plan, for better or worse.

Still reeling from the trauma of Hanna's abduction and dark fate, the Liars must shift their focus to another one of their own. In order to protect Alison from Uber A's threats, the PLLs snap into action at a chance to rescue her from the hospital. However, in doing so, they make a deadly mistake that changes everything.

With the fallout of Hanna’s abduction still weighing heavily on the PLLs, the Liars begin to grow suspicious of Elliott Rollins as Ali’s condition worsens. Tensions rise between Liam, Aria and Ezra as they work on the book together. Spencer and Caleb are on edge, as neither of them want to talk about the awkward elephant in the room. Meanwhile, Emily receives a disturbing phone call and tries to find a way to see Ali.

After Hanna’s shocking abduction by “Uber A,” the PLLs and company desperately race against the clock to save one of their own. The only way to do this is by handing over evidence of Charlotte’s real murderer to “Uber A.” In order to do so, the girls must decide what blatant lines they are willing to cross that they have never breached before; and once they cross that line, there is no turning back.