The plot is introduced in newspaper headlines that Fifi, Minnie Mouse's pekingese, has been dognapped, along with a description of the suspect, Peg Leg Pete.

A radio transmission detailing the suspect's get-away car is heard by police officer Mickey Mouse and his sidekick Donald Duck.

The pair soon see Peg Leg Pete speed by in the car and they chase after him, Mickey driving a motorcycle and Donald riding in a sidecar.

The film is filled with various gags showing the two law men as bumbling and incompetent, yet at every turn they are able to stay ahead of Pete, but not capture him.

Mickey and Donald restrain him with a corset, and they march Pete off to jail, accompanied by the instrumental "The Girl I Left Behind" with the now-free Fifi angrily barking at him.