 and her father. The next day she sits in the courtroom surrounded by people, watching the jurors walk into the courtroom. The Liars also enter the courtroom and sit on Alison's side to watch the trial. The prosecution leads with a compelling opening statement about Alison bullying Mona in High School, and the defense is about to lie to the jury about Alison being kidnapped and held captive for two-years. The prosecution informs them that Mona knew the truth about Alison lying about her story, and had the power to dismantle the story and ruin the fantasy created by Alison and her "followers". They press to say that is the reason why Alison punished Mona by killing her with a cruel and anonymous dead. Alison sits in absolute shock as she listens to the prosecution, tears in her eyes.
She tells Hanna later on in the prison, that she was communicating with someone through newspapers. They didn't know who really killed her mother, they were just torturing her. She also says that she believes this person was Mona since the texts ended after Mona was killed.
The next day the table, the prosecution plays the video of Mona being murdered by a blonde for Jason, the jury, and the courtroom. They tell everyone that Jason lied about Alison's whereabouts on the night of Mona's murder, asking why he decided to suddenly the truth. He admits that he doesn't know, but it wasn't something from the video. The prosecution asks if he told the police that the attacker in the video was Alison, and he admits that while he thought the attacker in the video could have been Alison he doesn't believe that now.
Jason visits Alison in prison after the day in prison, and they talk about the trial and what her lawyer thinks. He asks if there is anything he can do, and she suggests he leaves to avoid conflict. He tells her that he believes her - that she didn't kill Mona. She admits to not doing it but letting a lot of things happen that she shouldn't have.
Lesli Stone takes the stand as the prosecutions surprise witness, which rattles the defense quite a bit. Leslie brings in a postcard that Mona sent to Leslie about her being threatened by Alison, and was having a hard time dealing with it. The threat was that if Mona< "opened her trap about the kidnapping she'd be eaten by worms". When asked why Leslie had taken so long to bring the letter forward, she stated that she couldn't find it. She cries about how she couldn't realize the threat earlier and didn't take it seriously enough. She lies about how Alison's friends were on guard about anyone touching Mona's things or asking questions when she came to visit. She states that Hanna Marin practically stalked her the whole time she was there and didn't even let her into Mona's room.
Later, during a call with the Liars and Hanna (who is also in prison but is on another phone that is on speaker), they talk about Leslie suddenly appearing. Alison states that she's never even heard of Leslie Stone before, and Hanna informs her that she was a friend of Mona's from when she went to visit her Grandmothers. Alison is upset that Leslie managed to dig up some letter that made her look like a murderer, and admits that her defense teams don't have anything to prove them wrong. She tells the Liars that they have to find something because she spends life in prison because Mona wanted to use, "her last Laurel and Hardy stamp". She reveals that someone might have seen her at the park on Thanksgiving, but isn't sure if someone was really there or not, as all she heard was banging and saw a jacket. Before they can continue, their time is up and they are forced to hang up.
Rebecca proves that Alison couldn't have killed Mona, as Mon was hurled and thrown like a rag-doll. Something that Alison isn't capable of doing due to a fractured arm that never healed. However, the prosecution brings up a trophy that she won for archery that pokes holes in this story. Unbeknownst to everyone, Alison and her bunkmate had pre-rigged the targets so that she would win.
Later, the jury is finished deliberating and Alison stands in the courtroom ready to hear her fate. The Commonwealth has found Alison guilty of murder in the first degree, which means that Alison will spend the rest of her life in prison. Alison breaks down in tears as she is handcuffed by the guard, and the rest of the Liars are arrested as accessories to the murder.
The Liars are abducted on the way to the prison by A, who takes them to their dollhouse, where they wake up in exact replicas of their room. When the doors open they are reunited and are lead to a living room that looks exactly like the one Alison's house. In the room, a blonde wearing an Alison mask, Ali's yellow top, and clothes from when she went missing, is playing the piano. Hanna mistakes her for Alison at first. The blonde looks over and lowers the mask to reveal to the shock of everyone, a very much alive Mona. Hanna, with relief in her voice, realizes that it is Mona. However, Mona claims that while it's been a long time she hasn't changed that much and claims that she is Alison.
During tea-time, Spencer asks Mona where they are, but Mona claims that they are in her living room and asks why she's being such an imbecile. She offers Hanna a cookie and makes a snarky - and very much Ali-like comment, about Hanna not gaining all the weight back from one cookie. When Emily claims that they thought she was dead, Mona says that she's grateful for Mrs. Grunwald for saving her that night. Hanna states that she's really happy to see her and calls her Mona, which angers Mona as she believes she's Alison and loathes Mona. Emily tugs on Mona's hair and is shocked to learn that it's real, just dyed to match Alison's. Bells chime, and they follow, "Alison" to another room to play a game.
That night, Mona wakes up all the girls and tells them to follow her. She informs them of a generator that shuts down every night. She reveals the torture that she's had to endure since she's been kidnapped, and asks if her mom is okay. Hanna then realizes that Mona knows she's Mona, and she tells them that A wants her to be Alison, so that's who she is when A is watching. Hanna tells Mona that there was a trial for her alleged murder and that Alison was found guilty, which makes Mona smirk a little and scoffs.
Meanwhile, Alison is spending life in prison, when she is visited by Peter and Veronica. Alison enters the room in chains, handcuffs on her wrists and feet which are all connected. Peter and Veronica are worried about where the Liars are as they never made it to the prison. Alison is shocked to hear this, and reveals to them the truth about A, and how A killed Jessica and Mona. She also tells them that they never had any proof to prove that A was even real. She begs them to believe her, as she believes that A took them. When asked why she's decided to come forward now, she reveals that she is going to spend the rest of her life in prison and has nothing else to lose.
— Mona to Alison in "O Brother, Where Art Thou"
It has been three weeks since the events of "Welcome to the Dollhouse", and Alison has been released from prison and her guilty verdict is overturned. She holds a press conference outside of her house and asks Andrew Campbell, whom she believes to be A, to release her friends that he is holding captive in the dollhouse. Alison teams-up with Caleb and Ezra to track down A and find the Liars on their own. They are able to find the girls and free them for the Dollhouse, with Alison embracing Mona when she runs out of the Dollhouse. When the police announce that there is another girl in the Dollhouse, Mona, Alison, and Emily stand together and wait. Alison has her arm around Mona, and Mona standing close to Ali.
Mona returns from her trip to Saratoga and expresses her concerns to Hanna that Alison is planning her revenge against her, considering she sent her to jail. Later, Mona goes to the DiLaurentis house and drops off a letter in the mailbox for Alison. When confronted by Spencer, who saw her put the letter in the mailbox, Mona says that Ali didn't answer her calls so she decided to write her a letter.
The Liars (minus Alison) ask Mona if she saw anyone the night that Alison disappeared that could have been Charles and Mona admits that she didn't. Aria asks if she knows who she was talking to in Radley that stole the game from her, and she admits that half the time she was so drugged that she was hallucinating Alison.
That night, Alison calls Mona and asks her to pick her up from the hotel her father was keeping her at. When Mona pulls up Ali gets in, and thanks her for picking her up, as no one else had answered her phone calls. Mona states that she's just happy she could help, and knows that she owes her more than a car ride, especially after everything she's put her through. Ali starts to dial a number