The bandit Pratt, looking for Tim, who is responsible for the death of his two sons, attacks a caravan killing all the passengers. Harry, the vagabond, after having robbed the dead, casually meets Tim and they become friends. Running away together from Pratt, they reach Harry's farm, but their hiding place is soon discovered.

Franco, an Italian fisherman, witnesses a U.S. Air Force plane crash in the Mediterranean off Egypt carrying a nuclear weapon, and he is then persued by shady spy, named Ciccio, working for a spy organization led by the sinister Dr. Si (Yes) to find the atom bomb before anyone else does to blackmail the world, which leads to Franco and Ciccio forming an unlikely alliance to get the bomb for themselves.