The series is based on the eponymous work by English writer Frederick Forsyth. The story revolves around a professional assassin who is hired by a French militant dissident to kill the President of France, Charles de Gaulle. The leaders of the illegal organization OAS decide to eliminate the head of state through the hands of a hired killer. This becomes known to representatives of the French security forces, sparking a confrontation between the authorities and the members of the criminal group.