The Clampetts fly to London to give the Queen the deed to Canada they purchased. Waiting for an appointment with the Queen they stay at Clampett castle, where Granny is thinks they are at war with a neighboring castle.
In an attempt to get the Clampetts to move back to California, Mr. Drysdale tells Granny about the spirit of Lady Clementine. Her husband was murdered in the Clampett castle. Lady Clementine's ghost is going to return to seek revenge on the person who killed her husband; her little old grandmother.