Written by Graham Greene, a novelist comes to Vienna for a job, but he learns that his friend was killed. He questions witnesses, sees his friend, and helps the police with the investigation.
Vienna is divided into four zones by the US, UK, USSR, and France. Holly Martins (Joseph Cotton) arrives to work for his friend Harry Lime. He attends his funeral, and Major Calloway (Trevor Howard) gives him a ride. Calloway is a policeman and says Lime was involved in the black market and murder. Holly gets angry, and a cop hits him.
Crabbin (Wilfred Hyde-White) offers to help Holly, a writer of westerns, by having him lecture to his cultural society. Baron Kurtz (Ernst Deutsch) says he knew Lime and shows Holly the street where he was killed by his own driver's car. Holly goes to a play to find actress Anna Schmidt (Valli), who was at the funeral, and talks to her backstage.
In Lime's hotel room the porter (Paul Hoerbiger) tells Holly that a third man did not give evidence. Police are searching Anna's room. Calloway takes her passport and her. She admits to Holly that her papers were forged.
Holly goes to Lime's doctor Winkel, who pronounced Lime dead at the scene. Anna tells Calloway that she loved Limes. Baron Kurtz brings Lime's friend Popescu (Siegfried Breuer) to Holly and Anna. Popescu denies that a third man helped them carry Lime's body.
The porter tells Holly to come back in the evening. At night Holly learns that the porter was murdered. Some people try to follow Holly and Anna. A driver takes Holly in a speeding car to his lecture. Popescu asks questions, and two of his men chase Holly.
Holly goes to Calloway, who tells him that selling diluted penicillin caused deaths. Calloway warns Holly to leave town before he is murdered. Holly takes flowers to say goodbye to Anna. Outside Holly notices a man in a dark doorway. He sees it is Harry Lime (Orson Welles), who smiles and runs away.
Holly shows Calloway where Lime disappeared. They go down in the sewer. The grave is exhumed, and the dead man worked for Lime. Police arrest Anna, and Calloway offers to let her off for information. Holly tells Baron Kurtz that he wants to see Lime.
Holly meets Lime at an empty amusement park and asks him to help Anna. They go up high on a ferris wheel. Lime implies that murder for money is easy and suggests he could kill Holly, who warns Lime the police are after him. Holly goes to Calloway and asks him what he would pay him to get Lime. Holly wants to free Anna.
Anna sees Holly and gets off a train. He admits he is helping Calloway, but she rips up her papers. Holly tells Calloway that he is leaving on a plane. Calloway takes him to a hospital to see Lime's victims, and Holly agrees to be his decoy.
At night they wait, and Anna comes in. She warns Lime, who flees down the sewer. Police search in the sewer. Holly sees Lime, who shoots a cop. Lime climbs up to a street grate but can't get out. Calloway tells Holly to shoot. Lime and Holly look at each other, and a shot is heard.
At the burial Holly asks Calloway to help Anna. Holly decides to stay with her, but she walks past him.
This suspenseful mystery reflects the chaotic aftermath
and wild black market in eastern Europe after World War II. An
American writer is drawn into the intrigue and feels he must betray
his friend to help others, as killing becomes a way of ending
ruthless violence.