An American is on the run in the streets and back alleys of France.

Manhunt in Paris and as far as Belgium to catch an American gangster escaped from a police van.

The practice of Dr. Julien, a GP of Marseilles, consists mainly of drug-addicts. One day, one of his patient dies at his surgery and Julien yields to the temptation : he steals the dead man's money and hides the corpse in a trunk. But the whole thing is discovered and ... misinterpreted. The doctor is condemned for killing the junkie and sent to the Cayenne convict prison, from which he escapes. The Indians give him shelter and he is soon given the opportunity to return their good deed when a yellow fever epidemic strikes their tribe. A young woman helps to fight the disease and, thanks to her, Julien starts considering that a new life is possible for him.