John Rambo is a Vietnam War hero wandering from town to town searching for his old fellow soldiers. When he’s about to cross a little town to feed himself, Shérif Will Teasle arrest him for vagrancy. Detained and maltreated by some abusive policemen, Rambo become mad and angry. He run away in the wood after his was injured by several agents. Tracked like a beast, the ex-soldier is forced to kill a policeman in self-defence. Henceforth, the local police and the national guard roll out considerable resources to find the fugitive. Colonel Trautman, his mentor, take action and try to discorage both camp to killing one another while Rambo, injured, fight against the authorities.