A man named Dalton Russell sits in an unidentified cell and narrates how he has committed the perfect robbery. In New York, masked robbers, dressed as painters and using variants of the name “Steve” as aliases, seize control of a Manhattan bank and take the patrons and employees hostage. They divide the hostages into groups and hold them in different rooms, forcing them to don painters clothes identical to their own. The robbers rotate the hostages among various rooms and occasionally insert themselves covertly into the groups. They also take turns working on an unspecified project involving demolishing the floor in one of the bank’s storage rooms.
Police surround the bank, and Detectives Keith Frazier and Bill Mitchell take charge of the negotiations. Russell, the leader of the robbers, demands food, and the police supply them with pizzas whose boxes include listening devices. The bugs pick up a language which the police identify as Albanian. They discover that the conversations are in fact propaganda recordings of deceased Albanian leader Enver Hoxha, implying that the robbers anticipated the attempted surveillance.
When Arthur Case, chairman of the board of directors and founder of the bank, learns of the robbery taking place, he hires “fixer” Madeleine White to try to protect the contents of his safe deposit box within the bank. White arranges a conversation with Russell, who allows her to enter the bank and inspect the contents of the box, which include documents from Nazi Germany. Russell implies that Case started his bank with money that he received from the Nazis for unspecified services, resulting in the deaths of many Jewish people during World War II. White tells Russell that Case will pay him a substantial sum if he destroys the contents of the box.
Frazier demands to inspect the hostages before allowing the robbers to leave and Russell takes him on a tour of the bank. As he is being shown out, Frazier attacks Russell, but is restrained by another of the robbers. Afterwards he explains that he deliberately tried to provoke Russell and judges that the man is not a killer. However, this is disproven when the robbers execute one of the hostages.
The execution prompts an Emergency Services Unit team into action. They plan to storm the bank and use rubber bullets to knock out those inside. Frazier discovers that the robbers have planted a listening device on the police; aware of the police plans, the robbers detonate smoke grenades, remove their disguises, and exit the bank with the hostages. The police detain and question everyone but are unable to distinguish the identically dressed hostages from the robbers. A search of the bank reveals the robbers’ weapons were plastic replicas. They find props that show that the hostage execution was in fact faked, and no money or valuables appear to have been stolen. With no way to identify the suspects and unsure if a crime has even been committed, Frazier’s superior orders him to drop the case.
Frazier, however, searches the bank’s records and finds that safe deposit box number 392 has never appeared on any records since the bank’s founding in 1948. He obtains a search warrant to open it. He is then confronted by White, who informs him of Case’s Nazi dealings. She attempts to persuade Frazier to drop his investigation, but he refuses, playing a recording of an incriminating conversation that she had with him. White confronts Case, who admits that the box contained diamonds and a ring that he had taken from a Jewish friend whom he had betrayed to the Nazis.
Russell repeats his opening monologue, but with the revelation that he is in fact hiding behind a fake wall the robbers had constructed inside the bank’s supply room. He emerges a week after the robbery with the contents of Case’s safe deposit box, including incriminating documents and several bags of diamonds. On his way out, he bumps into Frazier, who does not recognize him. When Frazier opens the safe deposit box, he finds the ring and a note from Russell. Frazier confronts Case and urges White to contact the Office of War Crimes Issues at the State Department about Case’s war crimes. At home, Frazier finds a loose diamond, slipped into his pocket by Russell.