Herman Munster (Fred Gwynne) and his wife, Lily (Yvonne De Carlo) learn from Cavanaugh Munster's Will (law) that they have inherited an Manor house known as Munster Hall in Shroudshire, England, and that Herman has inherited the designation Lord of the Manor as "Lord Munster". The family boards the famous American transatlantic passenger ocean liner SS United States (in its last years) to England. Herman gets seasick, Marilyn (Debbie Watson (actor), replacing TV series original player Pat Priest (actress) in a controversial move) encounters a new love and suitor Roger Moresby (Robert Pine). Grandpa (Al Lewis (actor)) gets turned into a Gray wolf upon accidentally consuming a wolf pill. Grandpa has to be sneaked through British immigration and customs.