Contains spoilers for this episode.
George's successful evening with two women becomes a threat to his life when Blackadder learns that they are Wellington's nieces. The Duke challenges the Prince to a duel, and Baldrick suggests sending a substitute. Edmund is unwilling to fight himself, but hopes that his violent Scottish cousin MacAdder will accept the job. Since Wellington has not met George, the butler and Prince exchange identities to make the proposed substitution possible.
Edmund proves an impressive royal host while George discovers how painfully Wellington treats servants. MacAdder then refuses to help, preferring his own plans and a return to his fish-selling work. Edmund prepares to abandon the scheme until George offers him everything he owns. The prospect of a fortune persuades him to face the Duke. His last plan depends on a sword fight and a fire, but Wellington arrives with cannon, leaving little room for the manoeuvre Edmund intended.
The shot knocks Blackadder down, yet a cigarillo case in his pocket saves his life. Wellington declares honour satisfied. George reveals the identity swap, only to be shot as an insolent servant before he can convince the Duke. The King arrives and accepts Edmund as his son, allowing Blackadder to keep the princely role and dismiss Baldrick to remove the supposed dead butler. George briefly revives, remembers his own protective case, and then discovers that he left it elsewhere and dies.