Bart meets a comical sheriff (Edgar Buchanan) who is dead serious about killing him.

The Fenians, an Irish Revolutionary Brotherhood, are trained soldiers sworn to free Ireland from British rule. The Fenians have gathered in Dakota City to plan a march into Canada where they want to take hold of a small part of British property hostage in exchange for Ireland's freedom. After England pressures the United States to intervene, Beau Maverick is blackmailed into infiltrating the Fenians ranks by a shrewd Army colonel.

Bart is closer to tears than laughter when he is forced to battle the funniest and fastest gun in the West.