The federal agent Joe Dee Foster is currently investigating a serial killer, helped by doctor Animal who is isolated in a maximum security jail.

Italian immigrant Joe is hired by mobster Vince to kill a witness before he can testify against him. Joe dresses up as a policeman to be able to get close to his victim, but he's mistaken for a real cop by everyone and will reluctantly have to enforce the law to avoid blowing his cover.

The owner of an Italian natural food company has a heart attack and asks his son, Bernardo, to find the man who saved his life in World War II and bring him to his deathbed. He does so and finds the man in a sanitarium and must deal with his hijinks all the way back to Milan.