A young inductee into the military is given the task of looking after some chimpanzees used in the mysterious 'Project X'. Getting to know the chimps fairly well, he begins to suspect there is more to the secret project than he is being told.

During his long career, bounty hunter Ralph "Papa" Thorson has caught over 5,000 criminals. Now, while he is working on apprehending fugitives in Illinois, Texas and Nebraska, he himself is being hunted by a psychotic killer.