This film is based on the true character of Robert Denard (known as Bob Denard) in the 60's when he fights in Democratic Republic of Congo. As a mercenary, he defends President Mobutu who won his position after a putsch. Despite pressures from the French government who supports Mobutu's opponent Moïse Tshombé, Denard stays loyal to Mobutu until the very end when he unsterdands Mobutu wants him dead. Denard's only solution becomes to get rid of Mobutu, however the French governmet ends up changing side to support Mobutu. Luckily for him Denard manages to be rescued after head injury during combat against Mobutu's troops...