While investigating a labor racket on the San Francisco docks, Ironside fires on a dockworker, who is killed. But when the autopsy comes back, it's revealed that the slug went all the way through the man -- far too powerful for Ironside's .38 Police Special) and came from a different angle (Ironside was facing the man and the slug came from the side). To clear his own name, Ironside sends Ed Brown undercover with a fake mustache, where Ed meets the brother of the dead man and the racket leader -- who carries a gargantuan Magnum. To avenge the death of the dockworker, Ed is given a rifle and told to assassinate Ironside through his apartment window. But Ironside has a trick up his sleeve...