The House on 92nd Street

The film opens with documentary footage derived from FBI surveillance, showing officials at the German Embassy in Washington actively recruiting spies. The narration establishes the secrecy surrounding the atomic bomb project, Process 97. This framing sets the tense atmosphere for the espionage story to come.

A German spy is killed in a traffic accident, muttering Mr. Christopher as he dies. The FBI discovers a secret message pointing to Process 97, America's guarded atomic bomb project. This event triggers the spy investigation that drives the plot.

Bill Dietrich, a U.S. university student, is approached by German recruiters offering him a lucrative job. He feigns interest and then alerts the FBI to the recruitment. Agent Briggs recruits him as a double agent to infiltrate the German ring.

Dietrich is sent to Hamburg, Germany for six months of espionage training. During this time he learns spycraft and counterintelligence techniques. After completing training, he is sent back to the United States.

Back in the U.S., Dietrich is tasked with setting up a radio station on Long Island to relay secret shipping information. He also acts as paymaster for the spies meeting at a house on East 92nd Street. He is told that only a figure called Mr. Christopher can alter details of his assignment.

Dietrich hands his microfilmed credentials to the FBI. Agents decide to alter his authorized status so that he can contact nearly all the agents. This adjustment expands his access and heightens the risk of exposure.

The 92nd Street residence operates as a front for German spies, with a dress shop on the first floor. Elsa Gebhardt becomes Dietrich's contact but reacts with suspicion to his unusual authority. Germany's slow replies force Gebhardt to rely on Dietrich's access for now.

Gebhardt instructs Dietrich to transmit a key portion of Process 97 immediately. She seeks confirmation from Germany, but the communication is slow. Nevertheless, she grants Dietrich full access to the spy ring.

Dietrich's actions and a cigarette butt in Gebhardt's ashtray become a clue the FBI uses to identify Luise Vadja, and ultimately Charles Ogden Roper. Roper is arrested and questioned, and he confesses to hiding the last part of Process 97 in a copy of Spencer's First Principles at a bookstore.

Following Roper's confession, Briggs orders the immediate arrest of Gebhardt's ring. The investigation tightens around the German espionage operation and its key players.

Gebhardt finally receives a reply from Germany confirming her suspicions about Dietrich's limited authority and loyalty. The confirmation reinforces her position within the spy network and heightens the urgency of her mission.

Dietrich is abducted from the Long Island radio station and brought to the 92nd Street location. Gebhardt accelerates her plan to obtain the final vital papers on Process 97 before the FBI closes in.

Gebhardt injects Dietrich with scopolamine in an attempt to obtain information. Her building is surrounded by FBI agents, signaling an imminent takedown of the spy operation.

Gebhardt disguises herself as Mr. Christopher and tries to slip away with the final papers on Process 97. She cannot descend the fire escape, returns, and is accidentally shot by her own men. The rest of the ring is captured, and Dietrich is rescued.