Costa-Gavras (Z, STATE OF SIEGE, MISSING) made his directorial debut with this tightly constructed suspense thriller. Montand portrays a French police inspector investigating the murder of a woman who was sleeping in a lower berth on a moving train. Aided by his assistant Mann, Montand begins to track down all the passengers who were in the train compartment where the murder took place. Piccoli, an office worker who was on the train, volunteers information but afterward is found murdered. At the same time, two other passengers, Allegret and Perrin, attempt to avoid the police because the latter is a runaway who will be taken back to his parents if found. Perrin was hiding from the conductor in a berth and was aided by Allegret, a young woman traveling to a new job in Paris. After the murder, the pair stumble across the wallet of Signoret, an aging actress who also was a passenger on the train that night. They then go to her home to return it. Before knocking at her door, they notice she is being interrogated by Montand. Perrin and Allegret hide nearby and watch as a young man, Trintignant, slips out the back door of Signoret's house. During the interrogation, Signoret reveals that Perrin was hiding in an upper berth of the compartment. Soon after Montand leaves, Signoret is murdered. Eventually, the police determine that Trintignant was Signoret's lover, and when interrogated, the young man provides an airtight alibi. Meanwhile, Perrin overhears a plot by two men to kill Allegret and he tells the girl to hide out in a hotel. The young runaway then goes to Montand and spills everything he knows. When the police arrive, they thwart the murder attempt on Allegret and capture Trintignant. The suspect reveals that he was only an accomplice; the real killer is Montand's assistant Mann, who masterminded the whole scheme in order to pilfer Signoret's large bank account. Trintignant then goes on to state that Mann is out in the streets of Paris now, seeking to kill Perrin. Montand immediately sets out after Mann and following a thrilling chase, he saves Perrin and captures the killer. THE SLEEPING CAR MURDERS was sort of a family affair for Montand and Signoret, who were married, and for the beautiful Allegret, who is Signoret's daughter by writer director Yves Allegret. While the subject matter of this film is less political than those he would go on to make, Costa-Gavras' taut direction, coupled with a superb cast of foreign actors, propels this somewhat impenetrable mystery along at breakneck speed. It is an intriguing, highly entertaining thriller.