The Clampetts head to England to visit the castle Jed inherited. Misunderstandings abound, from Jethro mistaking San Francisco for London, to the impounding of Granny's medical supplies, to the real intentions of the elderly chemist.

Granny wants to leave England until she thinks the feudal system means feuding with the neighboring castle. Once back in America Jethro decides to continue his Robin Hood ways in a local version of Sherwood Forest.