In this episode we get more information on the connection between Lisbon and Bosco. When pedophile McTeer is found dead, Jane and the team discover Lisbon was originally the one who caught him in San Francisco, while Bosco was her boss. It was quite an accomplishment.
But when Lisbon's print is found on the murder weapon, things go bad. She gets taken off the case, and Bosco gets put on. At first she denies any involvement but she later confides in Jane that she can't actually remember anything from the night it took place.
Lisbon agrees to take a polygraph test, but shockingly, she fails it. After visiting the department therapist who tells her to calm down during polygraphs, she admits her alcoholic father had blackouts and did terrible things he later wouldn't remember. She begins to doubt her own innocence.
Jane hypnotizes Lisbon but they hit a wall when they get to the night of the murder. Meanwhile, Rigsby , Cho and Van Pelt do some of their own investigating which pisses Bosco off. But they find out McTeer's old cell mate "Dog" was the fiancée's brother that Jane and Van Pelt met at her house.
Turns out Dog was paid to lure McTeer into an alley but he has no idea who the shooter was. Meanwhile, Bosco confronts Lisbon about her team interfering in the case which is when Lisbon loses it and throws her chair out a window.
Cut to Lisbon having a party for one complete with booze and pills at her house. The whole department is visibly concerned about her. The therapist finds her at her house and in the midst of her craziness Lisbon ponders that she might have actually killed McTeer.
The therapist tries luring the truth out of her and starts giving Lisbon prompts about the murder scene hoping to elicit some memories. However, when the therapist mentions the sign of the cross, Lisbon cuts the craziness and realizes only the murderer would have known that detail. Come to find out, she and Jane set this trap for the therapist whom they suspected of drugging Lisbon and planting her fingerprint.
Lisbon is vindicated and all ends well.