The Letter of Marque
Patrick O'Brian
 In The Letter of Marque, Jack Aubrey, now a civilian, prepares the Surprise to sail as a privateer. The term "Letter of Marque" comes from the legal letters given to captains of private vessels allowing them to wage war in the name of the King against the King's enemies. While Jack often associated "privateers" with legalised pirates, he agrees to sail the Surprise, but always refers to the ship under the more respectable term "Letter of Marque." Jack is bitter and low-spirited about his dismissal from the Navy List, and dreads affronts and disrespectful treatment from any Royal Navy vessels and their officers. However, he is strongly supported by his crew - notably a group of smugglers and Sethian religious fanatics recruited at the little port of Shelmerston (fictional) in south-west England. The downfall of the traitors Wray and Ledward in the previous book has restored order in British intelligence circles, and Maturin - now the secret owner of Surprise - plans to use her privateering as cover for a covert anti-Spanish mission to South America. The ship is therefore under official protection to an extent and Aubrey's innocence is known privately to many, though the spies are still at large and politics will make his rehabilitation impossible without extraordinary deeds on his part. They depart on a cruise, during which Maturin's servant Padeen becomes a secret laudanum addict after painful dental surgery, diluting Maturin's own supplies with brandy in order to conceal his theft. Maturin is thus unknowingly weaned off his own addiction (though he later substitutes it with the practice of chewing Coca leaves). The Surprise captures an American privateer's consort, the Merlin, and then boards the privateer Spartan itself, retrieving its valuable cargo of quicksilver, looted from the Spanish barque Azul, as well as tricking her five prizes out of Horta harbour. These, together with his success in the cutting-out of the frigate Diane from the French port of Saint Martin-de-Rey despite serious wounds, make Aubrey both wealthy again and a popular hero. He is offered the opportunity to seek a free pardon, but angrily declines on the grounds that he is innocent and his friends fear that he has missed his chance of redemption. However, Aubrey's embarrassing father, a fugitive since his part in the stock-jobbing affair, is found dead in a ditch, and Aubrey is offered a Parliamentary seat by his cousin, Edward Norton, who owns the borough of Milport. This extra influence is enough for him to receive private assurances from Lord Melville, First Lord of the Admiralty, that he will indeed be restored to the Navy List as soon as the time is right. Maturin, in possession once more of Diana's magnificent Blue Peter diamond, decides to take it to her in Sweden. He sails part of the way on the old Leopard, now sadly reduced to a lowly transport ship, before re-joining the Surprise. He meets his wife Diana in Stockholm and is unsurprised to learn that the letter he sent to her from Gibraltar via Wray, accounting for his supposed infidelity, was never delivered. She also tells him she has not been unfaithful with Jagiello, and has been supporting herself by ascending - whilst mounted on a small Arab horse - in a hot-air balloon before an audience. Maturin is seriously injured in a fall after taking his usual dose of laudanum to soothe himself after their initial meeting, unaware that his tolerance has been reduced by Padeen's actions. Diana nurses him back to health and they become reconciled once more. When the Surprise returns from a trip to Riga to buy poldavy, Maturin hears from Martin about Padeen's laudanum addiction, discovered after he was caught siphoning laudanum from one of the carboys and replacing the tincture with brandy. Stephen is well enough to be finally transported back to the ship, accompanied by Colonel Jagiello's escort, and Diana embarks with him and Jack for home.