Roger Sartet is a condemned murderer who escapes from prison with the help of Vittorio Manalese, a Sicilian mobster.  The two plan to steal a collection of jewels that are scheduled to be displayed at an exhibition in Venice. They are swayed into a different course of action by Tony Nocisia, an American friend of Vittorio's, who suggests that rather than steal the jewels from the exhibition, they hijack the airplane that is scheduled to transport the jewels from Venice to their next port of call, New York City. Vittorio hides Roger at his home and arranges for his family to carry out the job. In the meantime, Roger begins an affair with Vittorio's daughter-in-law.  After the heist, the Manalese family goes into hiding in Paris and Vittorio, who has discovered the affair, lures Roger to Paris in order to rub him out. However, Roger arrives early and sees one of Vittorio's sons there at the airport.  He guesses what's up, and has the son arrested.  Vittorio is furious and is more determined than ever to have Roger killed, but his obsession may lead to the uncovering of their mutual crime.