Penniless Lord Whitebait (Naunton Wayne) plans to save his dwindling fortunes by opening his stately home Whitebait Manor, to the public. But public interest proves minimal, and with rapidly mounting debts and the spiralling costs of his daughter’s upcoming wedding threatening to ruin him, Whitebait is forced to take desperate measures. He and his servant Spankforth (Charles Heslop) plot to stage the theft of a valuable painting from Whitebait Manor, and they are aided in their scheme by Wilfred Sapling (Brian Rix), a plumber.