Jacques Mervel, also known as "L'Homme de la Jamaïque" makes use of his talents as a gun runner in Tangiers, Morocco. After triumphing over a rival gang, he decides to quit the job and to start a new life with Vicky, a pretty young nurse. In Paris, a doctor lets him know that he is affected by leprosy. In desperation, Jacques runs away from Vicky to spare her. When she realizes the reason why Jacques has disappeared from her life, she joins him with a view to helping him fight the disease.