Karl Atwood enlists his girlfriend Gia and three others to help plan and execute a major jewelry heist: Carson, fresh out of a Canadian prison; Nathan, an expert in phony identification; and a muscular Serbian named Zivkovic. The team of three trick a couple out of their home by sending them on a phony prize trip to Atlantic City, then drill through the empty house into the jewelry store next door. Unfortunately, during the heist, the daughter of the house comes home with her boyfriend to get some private time alone.
Karl kills Carson during the heist, shooting him four times. After leaving the jewelry store, he also shoots the two young lovers and escapes with $300 million in diamonds. Goren and Eames are called to the case and begin following clues from the dead bodies left behind, specifically the dead body of Carson, which was wearing expensive new clothes. Following the trail of stolen credit cards used to purchase the clothes and equipment, they collect different witness sketches of a single man and a single woman, Karl and Gia. A review of the security tapes from preceding days in the jewelry store produces a clear image of Gia, casing the joint.
Meanwhile, Karl lays down fresh red herrings for the cops to follow by killing a soldier of the Masucci family and leaving diamonds on the body. This briefly distracts the Captain into thinking it's a mob show, at least until the diamonds left behind are identified as being the lowest quality and least expensive diamonds in the lot that was stolen.
With the assistance of a heavily tattooed friend, Goren is able to tie the homemade prison tattoo on Carson's body to a prison in Canada. With Carson's identity determined, the detectives are able to pull his record, and learn that he has skipped parole to enter the US, likely by train, which undergo less security. A canvas at Penn Station produces a witness, who is able to identify a mug shot of Zivkovic, who came to pick him up. A background check of Zivkovic results in an address, which the detectives raid.
The detectives find the house empty, but do seize a piece of expensive forgery equipment, left behind when the group abandoned the site. Nathan calls Karl to tell him that it is missing, and Karl orders him to buy a new one. Goren and Eames are ready for him, and Nathan is arrested when he goes to make the purchase. With the threat of the death penalty hanging over his head, he cuts a deal to help bring Karl in. He places a telephone call to Karl so that police can trace Karl's location, but Karl catches on and escapes. Goren and Eames arrive just in time to catch Gia, who was doing laundry and was left behind.
Goren convinces Gia during interrogation that Karl is only using her, and that he was having a relationship with Carson in prison. He shows Gia files that Carson had AIDS, and that through Karl, she is also infected. He promises to make sure she gets good medical care in prison if she helps him bring Karl in. With Carver's cooperation, he lets her go so she can bring Karl in. She retrieves the diamonds and is met by Karl, who is suspicious about why the police released her, and threatens to kill her. She tells him about Goren's attempt to convince her that he has AIDS, and denies working for the police. In order to persuade him that she does not believe the police, she is forced to sleep with him.
The buyers for the diamonds arrive at the hotel, examine the goods, and agree to pay Karl. Karl rejoices and goes to the other room to retrieve the rest of the diamonds. When he returns, he finds the police there and everyone already under arrest. Goren and Eames tell Gia that she is not actually infected with HIV, and the criminals are led away.