Benson and Stabler show up at the scene of a brutal rape. Benson agrees to ride with Ashley in the ambulance and is surprised when Ashley reacts violently to seeing Benson and the paramedics prepare to sedate her. Later on at the hospital, Benson meets up with Ashley's foster parents, who get defensive when Benson wants to know if Ashley has a history of abuse.
The detectives discover Ashley's past includes a mom in prison and a father whom she's never met. Ashley also has a close relationship with her uncle, Richard Tyler, who has a history of molesting Ashley. Stabler and Benson pay a visit to Richard, who is taking a shower as they search his apartment. They find weed and an Oxycontin prescription.
Richard denies the claim that he touched his niece and says he's the only family she has. He also goes on to tell a story of how Ashley's mom got wrapped up in a drug ring while in prison and when she tried to get out of it, the prison guard paid a visit to Richard's marijuana garden and raped Ashley. Ashley confirms the story, but can't identify the man. All Ashley can remember is the man said he did it to get revenge on her mother.
The detectives discover the rape kit was taken from the hospital. They know the only person who can help them get it back and identify the rapist is Ashley's mother, Risa. They now know her mother is being raped in prison by the same man. Stabler goes undercover to pay Risa a visit. The visit is cut short and Stabler wants answers from the warden.
Munch finds out that Sealview Prison has a record of sexual assaults but the cases never make it to court. This infuriates Benson and she pleads with Cragen to let her go undercover. He doesn't like the idea, especially because she insists that nobody, not even the warden, can know about her undercover assignment.
Benson goes undercover as a junkie who gets sentenced to Sealview. She has to go through strip searches, communal showers and more searches. When a male guard gropes her, she attacks him, only to get hit with a nightstick by another guard. She falls to the floor and is shocked to see that the guard who hit her is Fin; he is undercover to keep an eye on Benson. As she's getting her wound treated, Benson discovers Risa committed suicide the day before.
Warner lets Stabler know that Risa never committed suicide, she was murdered. Benson is trying to fit into her new surroundings. One inmate tells that if she wants a "fix," she needs to show the guards that she will earn it. Just then, Fin and another guard, Matthew Parker, walk in. Parker makes a few derogatory comments to Benson before leaving. Benson signals to Fin to have Parker checked out at the SVU.
Ashley is admitted into the hospital with advanced-stage TB. Ashley's mom tested negative, meaning Ashley had to have been infected by her rapist. Sealview goes on lockdown until every inmate and guard can be tested. Stabler hopes this will lead to Ashley's rapist-turned-Risa's murderer. Fin learns that he and Benson will be on lockdown in the prison for three days until the TB results come back.
While the nurse is busy getting more syringes for TB testing, Parker is excused while Fin has to wait. Back in the cafeteria, Benson demands to know what was going on with the TB testing, then other inmates want to know, too, and a riot begins. Once the inmates are broken up, Captain Harris grabs Benson and begins to lead her downstairs to an isolated hallway. She keeps apologizing for her behavior, but Harris tells her it's too late and ushers her onto a dirty mattress.
Harris handcuffs Benson and slams her against the wall and begins to grope her. As soon as he is ready to undress her, he un-cuffs her and she turns around and punches him. She manages to escape and run down the dark hall. Harris grabs his gun and whispers to himself that she has no escape.
Harris walks up and down the halls looking for Benson, who is hiding behind some crates. As he kicks over chairs and boxes looking for her, he warns her how much trouble she is in once he finds her. Meanwhile, Fin breaks free from the testing line and grabs an inmate to help him search for Benson. She claims she knows where the guards take the inmates for sex. Fin follows her and promises her a cigarette for her help.
Once Harris finds Benson, he strikes her with his nightstick, handcuffs her to a locked door, and attempts to rape her. Just as he is about to, Fin finds them and announces to Harris that he's under arrest. A visibly shaken Benson announces that she is a cop, too. Harris is shocked as he is handcuffed and taken in to the SVU.
Benson interrogates Harris back at the SVU. She brings up his resume -" he's held positions at maximum-security prisons for men, but kept getting transferred until he ended up at a female state prison. She taunts him with the fact that he wasn't man enough to keep a job at a male prison so he had to work at a female one. This visibly upsets Harris, who is handcuffed to the table in the interrogation room.
Benson strikes a nerve when she accuses Harris of hating women and that must mean he is attracted to men. He tries to leap at her, but his handcuffs prevent him from doing anything. Just then, they are interrupted when Harris' attorney walks in and announces his client will be leaving -" he and Officer Parker both tested negative for TB, and Ashley was infected while staying in a group home. Benson is shocked that Harris is going to be released.
Benson is still at work staring at Harris' picture when Stabler approaches her and tells her to not worry, they will get Harris eventually for his crimes. She had found out earlier that Ashley had taken a turn for the worse, making it more difficult for her to identify Harris as her attacker. Stabler wants details on what happened to Benson in that basement and she refuses to talk.
Benson receives a call that Ashley is better and she can visit her in quarantine. Ashley wants her attacker dead for what he did to her mother. She plans on being released soon, but doesn't even want to think about her rape. Benson wants Ashley to help identify her attacker, because even though she never saw his face, she could identify his body.
Ashley remembers a mole on Harris' genitals and Benson realizes it was Harris who raped her. Stabler, Benson, and Sealview's warden show up to arrest Harris in front of the cheering inmates. Back at the lab, he's humiliated as Warner takes pictures of his genitals while Stabler and Benson watch. Later on, Warner asks Benson how she knew about the mole and Benson goes silent. She then asks if Benson was raped in the basement, she tearfully says it's the closest she has ever come to it.