Brandon and Philip are two young men who share a New York apartment. They consider themselves intellectually superior to their friend David Kentley and as a consequence decide to murder him. Together they strangle David with a rope and placing the body in an old chest, they proceed to hold a small party. The guests include David's father, his fiancée Janet and their old schoolteacher Rupert from whom they mistakenly took their ideas. As Brandon becomes increasingly more daring, Rupert begins to suspect.

Harry Caul is a devout Catholic and a lover of jazz music who plays his saxophone while listening to his jazz records. He is a San Francisco-based electronic surveillance expert who owns and operates his own small surveillance business. He is renowned within the profession as being the best, one who designs and constructs his own surveillance equipment. He is an intensely private and solitary man in both his personal and professional life, which especially irks Stan, his business associate who often feels shut out of what is happening with their work. This privacy, which includes not letting anyone into his apartment and always telephoning his clients from pay phones, is in part intended to control what happens around him. His and Stan's latest job, a difficult one, is to record the private discussion of a young male/female couple meeting in crowded and noisy Union Square. The arrangement with his client, known only to him as "the director", is to provide the audio recording of the ...

In London, wealthy Margot Mary Wendice had a brief love affair with the American writer Mark Halliday while her husband and professional tennis player Tony Wendice was on a tennis tour. Tony quits playing to dedicate to his wife and finds a regular job. She decides to give him a second chance for their marriage. When Mark arrives from America to visit the couple, Margot tells him that she had destroyed all his letters but one that was stolen. Subsequently she was blackmailed, but she had never retrieved the stolen letter. Tony arrives home, claims that he needs to work and asks Margot to go with Mark to the theater. Meanwhile Tony calls Captain Lesgate (aka Charles Alexander Swann who studied with him at college) and blackmails him to murder his wife, so that he can inherit her fortune. But there is no perfect crime, and things do not work as planned.

Travellers on a trans-European train are delayed for a night due to bad weather in a small fictional country called Mandrika. The passengers cram into the small village hotel where socialite Iris Henderson meets an old governess called Miss Froy. Shortly after the journey restarts, Miss Froy disappears.