In 1848, Hornblower, now 72, is enjoying a comfortable retirement on his country estate at Smallbridge, Kent. Recently promoted to the well-paid but honorary rank of Admiral of the Fleet, he reflects that life as a country gentleman is pleasant and secure but dull. Hornblower is still married to the upper-class Lady Barbara, his son Richard is a colonel in the Guards, and his sailor-servant Brown still attends him, although now as a butler.
Late one stormy night, a well dressed Frenchman, claiming to be Napoleon, arrives at the front door of Hornblower's mansion to urgently request help. The seemingly eccentric visitor has been traveling by rail to Dover to take ship for France. However a landslip has delayed the train near Smallbridge Park and he is seeking assistance to complete his journey. Barbara is favorably impressed with the man's charming manners and persuades her husband to provide a carriage to oblige the visitor, although Hornblower remains privately convinced that the Frenchman is a lunatic.
A month later, the Hornblowers find that their caller was Prince Louis Napoleon Bonaparte: nephew of Napoleon I and the future Emperor Napoleon III. He was on his way to Paris to contest the office of President of France. After winning the election, the Prince-President confers on Hornblower the insignia of a Chevalier of the Legion of Honour and presents a sapphire to his wife, in gratitude for their timely aid.