A bunch of college kids are playing an Escape the Room type game. One girl, Bethany, is tied up. She and another girl run towards an exit, but it's locked. The game master laughs and lets them out. As he is teasing the girls about coming close but ultimately failing the challenge, gunshots are heard, and they're not part of the game. A girl is found dead on the floor.
When Antonio and Laura get there, the uniform makes a big deal out of how they are called for the rich kids. It turns out that the victim, Kennedy Malone, is the daughter of a very rich man, and the top suspect is Abigail Chapman -- a classmate who stood trial for murder in Spain.
The investigators talk to Abigail's boyfriend, Todd, who denies knowing where she is but is clearly hiding something. They follow Todd home and see a man with a gun enter the premises. The man claims to be a bounty hunter from Spain and offers Antonio 10% if he can take Abigail. Antonio punches him and he is arrested. Abigail is taken to the quad room also for interrogation, where she has some sort of psychotic episode and attacks Antonio.
While Abigail is recovering in the hospital, the SA's office has to deal with Spain wanting to extradite her to stand re-trial. The judge gives them 48 hours to charge her with something or turn her over. After interviewing Abigail again, they realize she heard someone hiding the murder weapon. They find a gun hidden in a torture device. The gun was registered to Kennedy, the victim.
Further investigation reveals that Kennedy's father gave her a gun for protection on her 21st birthday and that she had problems at school with a professor who was strongly against gun rights and didn't like her organizing a pro-gun rally. Another student, Bethany, is a poor girl from Kansas who Abigail claims to have been friends with. Bethany won't talk to the investigators, but they get her prints when they show her some mug shots and she is confirmed to be the murderer and arrested in the library.
Bethany's attorney tries to claim self-defense and paints a picture of Bethany as a sweet, innocent girl while Kennedy was a nut case and spoiled brat whose father got her everything. Bethany claims never to have met Kennedy before and that she grabbed the gun from her when Kennedy pointed it at her and they struggled and it went off. She was sure Kennedy would shoot her because only nut cases have guns.
Valdez worries their case is sunk but Laura realizes Bethany is lying about not knowing Kennedy and convinces Abigail to testify against her. Abigail is reluctant because of her own experience with wrongful arrest but does so. However, Bethany's lawyer accuses her of being a murderer and nearly causes another psychotic episode. But when Bethany is recalled to the stand, Stone is able to get her to admit that she saw the professor as a father figure and killed Kennedy because she was issuing a complaint against him for his harassment of her.
Jeffries calls the State Department to stop Abigail's extradition since she was so instrumental in getting a conviction in this case.