Psychotic bandit Bill San Antonio (Frank Wolff) kills all the passengers on a train and steals a fortune in gold. Hutch Bessy (Bud Spencer), an insurance investigator, and his gunslinger partner, Cat Stevens (Terence Hill), go on the hunt for Bill, hoping to retrieve the loot. Unfortunately, outlaws take Hutch and Cat prisoner. Cat manages to get away and saves Hutch's life. When Cat is kidnapped later by other crooks, Hutch has to reciprocate. But they still have Bill to worry about.