Transferred aboard Indefatigable, Midshipman Hornblower is put in command of the French ship Marie Galante, carrying a cargo of rice from New Orleans, by order of Captain Pellew after it is taken as a prize.
As Pique is the faster sailer, Hornblower devises a plan to slow her down: he sets a fire, which soon spreads to the very flammable paint locker.
Hornblower's fears of reprimand for losing Marie Galante are quickly extinguished by the offhanded dismissal of the incident by Captain Pellew.
However, instead of taking credit for the fire, Hornblower suggests that there may have been spontaneous combustion in the paint locker, as a way of punishing himself for losing Marie Galante in the first place.
Upon returning to Indefatigable, Hornblower is assigned a role of loosening the sail by Captain Pellew in his plan to take the French corvette Papillon.
Given the success of their mission Hornblower realises the loss of the jolly boat will not be held against him, but still regrets the inevitable death of Hales.
He gains a clue from Finch, another of his men, who suffers from delusions and claims that "God's in the maintop, but the Devil's in the cable tier, but only in the dog watches".
Later, in action against a French ship, Hornblower and Finch are firing a swivel gun from the mizzen-top when the mast is hit and begins to fall.
Hornblower takes part in the attempted invasion of France by British and French Royalist forces at Quiberon in order to support the failed Revolt in the Vendée.
Hornblower is ordered ashore with his seamen acting as gunners, and gains his first experience of land warfare and the horrors of the Revolution, including the guillotine.
Since Spain becomes officially neutral, the British ship of war is forced to leave, passing prisoner-rowed galleys still maintained by the conservative Spanish navy.
Spain has completed its political turnaround and joined France in an alliance by the time Indefatigable is escorting another ship through the Straits of Gibraltar.
Acting-Lieutenant Hornblower accompanies the diplomat Mr. Tapling to buy cattle and grain from the Bey of Oran to resupply the fleet.
However, an outbreak of the bubonic plague in the city forces Hornblower, Tapling and his boat-crew to take refuge aboard the transport ship Caroline and remain in quarantine for three weeks until they are clear of infection.
Hornblower is given command of the French prize Le Reve and ordered to return to England with dispatches and, to his astonishment, a passenger – the Duchess of Wharfedale.
Anticipating capture Hornblower prepares to throw his dispatches overboard, but is persuaded by the Duchess, who also reveals her true identity as a popular actress, to allow her to conceal them under her clothes, as she is sure to be repatriated immediately.
Much later, while in a Spanish prison at Ferrol, he receives a letter from her detailing her successful return to England, and another from the Admiralty confirming his promotion to lieutenant.
Four of the episodes form the basis for the first four instalments of the series of TV films Hornblower which were released both in the US and the UK, sometimes with alternate titles.