In this novel, Aubrey and Maturin complete their circumnavigation of the globe begun in The Thirteen Gun Salute and continued through The Nutmeg of Consolation, Clarissa Oakes/The Truelove, and The Wine-Dark Sea.
After a long-awaited stay at home in England, Commodore Aubrey is given a squadron to conduct a mission against slave ships in West Africa and then he and Maturin are sent against Napoleon's Navy.
[1] What keeps one reading is the "improbable, delightful friendship between the two men"[2] With part of the story on land, dealing with family issues, the impeccable writing marks O'Brian as the heir "of Jane Austen herself.
It is not even, in the end, about sailing, although it captures with unique clarity the terrible beauty and wondrous excitement, the deep awe and hard work, that are so much the experience of keeping a ship afloat and on its voyage.
When Maturin does reach home with Sarah and Emily, he finds his young daughter Brigid in the care of Clarissa Oakes, now widowed.
To secure his fortune and his family, Maturin asks Aubrey for the Ringle to move his cash to Corunna and to carry Clarissa, Padeen and Brigid to live at the Benedictine house in Ávila, Spain, for safety.
Aubrey is in a bad mood, felt throughout the ships, until Maturin tells him that Pastor Hinksey is to be married and set up in India; jealousy had gnawed at him.
As he recuperates, they stop at St Thomas island for medical supplies; two officers (one from Stately, one from Thames) step ashore for a duel by guns, each fatally wounded, resolving nothing.
After tending the wounded, Maturin learns from his friend Roche that the flags are at half-staff on account of the death of a minor royal, the Duke of Habachtsthal, who has committed suicide.
See also Recurring characters in the Aubrey–Maturin series Jack Aubrey's squadron: Arrive upon hearing the gunfire in Bere Haven, Ireland Slave ship
[2] On the other hand, he remarks that "it is not the sea battles that keep us turning the pages, but rather the improbable, delightful friendship between the two men as well as their relationships with their families and shipmates."
The main characters "are complex men, expertly portrayed", and both leave home for their naval mission unhappy due to family concerns.
The naval mission begins on the west coast of Africa to intercept slave ships, the trade already outlawed in England, then moves on to surprise a French expedition.
It is not even, in the end, about sailing, although it captures with unique clarity the terrible beauty and wondrous excitement, the deep awe and hard work, that are so much the experience of keeping a ship afloat and on its voyage.
Aubrey's first sight of slaves aboard a ship designed for that trade deeply affected him, though he did not share Maturin's fierce abolitionist views, a way to depict the long struggle to end slavery in the UK and its colonies and territories.
"[6] Thus the vessel is named Ringle, and its amazing sailing properties well-described, and used for critical parts of the plot, like saving Maturin's family and fortune.