La culminación y cierre del impresionante ciclo de las aventuras de Aubrey y Maturin es una novela basada de nuevo en la biografía de Thomas Cochrane, en este caso en su viaje con destino a Chile para contribuir a la independencia de ese país. Sin embargo, por el camino estará a punto de irse a pique y tendrá que enfrentarse a los más variados problemas (deserciones, adulterios, espionaje...), aunque por fin parece que su tan ansiado ascenso empieza aperfilarse en el horizonte.

Simply excellent. I'm just sad I've come to the end of such an excellent series.

Will never be matched. ( )

So here ends the Aubrey-Maturin epic saga, though a further book was left incomplete at the time of O'Brian's death. It's a good thing, really. The struggle to find anything original for the pair to do, growing ever more difficult since as far back as book 10, had by this point proved impossible. With the Napoleonic Wars over, reasons for further voyages were also getting contrived. Maturin's drug abuse with no real consequence was getting a little preposterous. Hence ending on the upbeat note of Aubrey finally gaining his Admiral's flag and sailing off to take up command of a squadron on a ship-of-the-line seems the perfect conclusion. ( )

Blue at the Mizzen, Patrick O’Brian’s twentieth and final complete book in his Aubrey-Maturin series, picks up shortly after the events of The Hundred Days, with Captain Jack Aubrey and Dr. Stephen Maturin embarking on their mission to Chile that was laid out during The Yellow Admiral, but briefly interrupted by Napoleon’s final attempt to reclaim power. A collision with a Nordic timber ship further delays Surprise, forcing her to undergo temporary repairs in the hopes of reaching Funchal for more lasting work, only the crew finds the Funchal shipyard aflame. Maturin receives word that the Chilean independence movement has factionalized, so he boards Ringle in order to hasten to London to consult with Sir Joseph Blaine. There, he looks in on his daughter, Brigid, and Jack’s family at Woolcombe, learning that Surprise has returned for repairs. In London, the Duke of Clarence asks Jack to take Horatio Hanson aboard as a midshipman and Jack, though initially reluctant, finds that the boy is a prodigious mathematical talent and accepts him. With the Surprise repaired, the ship and crew head for Chile, picking up Dr. Amos Jacob in Funchal and stopping in Freetown, Sierra Leone to resupply and for Dr. Maturin to propose marriage to Christine Wood, a widow of his acquaintance. Having had an unhappy prior marriage, she turns him down, but plans to visit England and offers Stephen hope for the future.

In Chile, Jack finds conflicting orders, but works to aid the local juntas, in particular the Supreme Director, General Bernardo O’Higgins, and Colonel Eduardo Valdes, a cousin of Maturin’s. Maturin and Dr. Jacob learn that the Peruvian forces, loyal to the Spanish king, plan to invade Chile, so they confront them at Valdivia, bombarding a fort and seizing gold, silver, and other supplies. Despite the success, local sentiment turns against the British to the point that the junta plans to impound Surprise, so Aubrey makes a plan to cut out the Peruvian frigate Esmeralda, strengthen the Chilean navy, and thereby build up goodwill. The plan works, though Aubrey is wounded. As he recovers, Stephen and Dr. Jacob send word to Sir Joseph while Ringle brings the news to Valparaiso. Despite much celebration, Aubrey insists that his sailors must be paid or depart, and Don Miguel Carrera, the president of the Valparasio junta, authorizes the first of the funds. Aubrey begins training the Chilean navy as Surprise surveys the coast, while orders arrive for Aubrey to repair to HMS Implacable in the River Plate, take command of the South African squadron, and hoist his pennant as Rear Admiral of the Blue. Carrera states that it will take longer to complete the payments, so Aubrey respectfully departs Chile and accepts his long-sought promotion.

Blue at the Mizzen has all the character moments fans of this series have come to love, with Horatio Hanson being a fine addition to the crew. Stephen’s time with Christine Wood offers some moments of joy following his sorrow in the previous novel. Like The Yellow Admiral and The Hundred Days, O’Brian discusses the effects of changing land policy, specifically enclosure, and how the war’s end impacts not just sailors and soldiers, but every level of the British economy that had been on a war-footing for two decades. Though O’Brian did not intend this as his final novel, its publication a mere two months before his death made it so. As such, it will bring fans joy with the promise of happiness for the two characters that have led the series over its twenty novels. This Folio Society edition reprints the original text with insets containing historical portraits and sketches to illustrate some of the scenes and an endpaper map centered on the Atlantic Ocean, with several labeled cities from throughout the series and an inset of the tip of South America. ( )

The Surprise had been a man-of-war vessel. It's newest assignment as a research vessel was a hydrographical assessment. Captain Jack Aubrey has been charged with conducting a survey of Magellan's Strait, the Horn, and the Chile coast. Additionally, Aubrey agreed to help Chile assert its independence from Spain. Aubrey just can't stay away from a good political conflict and his decision has its consequences.
Blue at the Mizzen focuses a little more on the personal lives of Jack Aubrey and especially Doctor Stephen Maturin, which was a pleasant surprise. Jack's brief romance with a married woman, his cousin Isobel was short lived, but Maturin's was a little more substantial. As a widower, he travels to Africa where his birding adventure with fellow bird enthusiast Christine sparks a romance. While his proposal goes unaccepted in the heat of the moment, he continues to write to her from sea and his letters become a diary of sorts (extremely helpful with the narrative).
Of course O'Brian adds plenty of swashbuckling drama as well as international intrigue to his plot besides romance.