Plot

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?

Open with the girls having been brought to an apartment by Noel. He leaves and Alison walks in. They tell her they think her mother is A and she doesn't look shocked. She tells the girls she's ready to tell them everything and if they can't figure things out that night she's going to disappear again, "this time for good."

Holbrook interviews CeCe. She tells him she knows who killed the girl the police thought was Alison. She says it's the same person who is actively trying to hurt Alison, whom she can prove is alive.

Alison flashes back to being with Ian when Melissa arrives and confronts him. While Melissa and Ian argue, Alison copies his hard drive. She uses the video to intimidate Jenna, but gets a text from A saying she was going to kill her. This means Jenna wasn't A.

Holbrook is having Hanna's home searched. He tells Veronica they have probable cause the girls know the whereabouts of a missing person and shows her a picture of them talking to Alison. Melissa walks in.

Alison tells the girls when she returned home she got yet another threat from A. That night Alison and Jessica got in a fight because she didn't want her daughter going on. She warns about the Hastings family. Alison takes her mother's sleeping pills. Alison meets the girls at the barn and slips some of the pills into their drink, hoping to cross them off if another A threat arrived. She met with Toby that night and said she knew he wasn't A, either. Ezra pulls up and Alison gets in the car. He won't let her leave.

At the station Holbrook asks Veronica about Spencer's recent activities. She doesn't like it and wants to contact her husband. An officer tells Holbrook they have a warrant for the GPS signal on the girls' phones. Melissa is being interviewed in another room, as is Peter, who doesn't know Veronica is there.

Alison tells the girls about meeting Ezra at a pub while hanging out with CeCe. Alison tricks him into thinking she's a literature buff. Alison apologizes for Aria for "everything." The night Alison drugged the girls Ezra was mad because he'd just discovered she was actually in high school. He says he won't see her anymore. Alison then met Ian and threatened him that if she gets another text she's sending him to jail. He warns her that some of the videos could bring "everybody down, including your family."

In present day Alison tells Aria that Ezra is trying to save her, thinking that it could get her back.

That night Alison returned to the girls and found an angry Spencer waiting for her.

Holbrook asks Peter about hiring a private investigator that summer and shows him the file with Spencer's name all over it. Holbrook references Spencer's "erratic" behavior and Peter stops talking. In the hall Holbrook is told the girls are in Philly. Peter sees Melissa and finds out Veronica is also there. Peter begins to panic and Melissa seems to think her father believes Spencer killed that girl.

That night in the barn Spencer and Alison argue. Spencer grabs the shovel and eventually falls over. Alison sees Spencer speed pills and follows after her. Spencer cries and begs her not to tell anybody. Alison promises not to tell anybody. Later on that night she sees Byron and threatens him with the tapes. Alison didn't receive any more texts that night, but returns home to find her mother staring out the window. Alison gets hit in the head with a rock while her mother looks on. This seems to prove Spencer couldn't have hurt the other girl and Jessica saw who did. We see Jessica shoveling dirt over Alison, who she thought was dead.

In present day Alison tells the girls she tried to tell her mother she was alive but she couldn't speak. Alison heard her mother say "what have you done?" which means Jessica was trying to protect somebody. That night Alison left the hospital alone and Mona found her walking along the road. The go to a motel under a fake name and Mona thinks that perhaps Alison should let A think she's dead by disappearing. Mona puts her to sleep and goes next door to her "A headquarters." The next morning Alison thanks Mona for saving her life and leaves. Alison tells the girls in present day that Mona "played me like a fool."

In the police station Melissa tells Peter that "Spencer didn't kill that girl." She whispers something in his ear and his eyes get huge.

The girls tell Alison not to leave, even though they still don't know the identity of A. We see Alison was the hooded person who saved Spencer from Ian. She was also at the lodge trying to make sure they were safe. The girls see the police outside. Just then a hooded figure begins shooting at them and chasing them. They flee to a roof and find themselves trapped. Ezra shows up and gets in a wrestling match with the hooded figure. The hooded person ends up jumping to the next rooftop. The girls turn back and see that Ezra was shot in the exchange.

We see Jessica's unconscious body being dragged and then placed in a grave.