Alain Lefevre is a boxer paid by a Marseille mobster to take a dive. When he wins the fight he attempts to flee to America with the mobster's girlfriend Katrina. This plan fails and he seeks escape by joining the foreign legion. As part of the legion he tangles with abusive lieutenant Steinkampf and bonds with legionnaires Luther, Mackintosh and Rosetti.
Jean Claude Van Damme plays a dual role as Alex and Chad, twins separated at the death of their parents. Chad is raised by a family retainer in Paris, Alex becomes a petty crook in Hong Kong. Seeing a picture of Alex, Chad rejoins him and convinces him that his rival in Hong Kong is also the man who killed their parents. Alex is suspicious of Chad, especially when it comes to his girlfriend.