Joss Beaumont (Jean-Paul Belmondo) is a French spy given the assignment of killing an African dictator, and when he arrives in Africa to do so, he is captured and put in prison. The political winds had changed - the dictator is now an ally - and the best way to handle the agent is to keep him in jail. Naturally at odds now with his former bosses and with an ax to grind for his own incarceration, the agent escapes after two years in prison and heads back to Paris where he announces that he is going to finish his assassination job during the coming diplomatic visit of the African leader. Once aware of his intent, the French government sets up one trap after another, but to no avail - the agent remains free and there is no doubt that he has the full capacity to do exactly what he says.