The novel opens in Carlisle Bay, Barbados where Lieutenant Ramage, commander of the brig HMS Triton, is receiving orders, along with the masters of 49 merchantmen and four other escorts, for a convoy to Kingston, Jamaica. Ramage has again found himself under the command of two of his father’s enemies, men who contrived Ramage’s court martial on charges of cowardice when he was in the Mediterannean. He knows the trip will be fraught with professional danger because of his commander, but they are departing at the beginning of hurricane season and the convoy commander, Ramage’s nemesis Admiral Goddard, alludes to one of the merchantmen carrying a very valuable cargo but doesn’t specify which ship.
Major spoilers follow.
Ramage senses in the briefing that Goddard and his lackey, Captain Croucher, are afraid of the master of one of the merchantmen. The master, Yorke, is familiar with Ramage’s exploits at the Battle of Cape St Vincent and in suppressing privateers operating out of St. Lucia and he and Ramage strike up a friendship. Meanwhile, Ramage’s worst fears are realized when he is called to a private conference with Goddard and Croucher where they virtually promise to find reason to bring him to court martial and ruin.
As it turns out, the precious cargo is carried by Yorke and it is a party of very prominent French Royalists acting under direction of the Foreign Office. By happenstance, they are also acquaintances of the Marchesa di Volterra and are familiar with her escape from Napoleon’s troops and Ramage’s role in the rescue.
Some days into the voyage, Ramage has noticed suspicious behavior by a ship which joined the convoy just as it departed. He reports his suspicions to Croucher, who does nothing. The ship turns out to be a French privateer and Ramage plays the key role in exposing and taking her. Goddard and Croucher contrive to blame Ramage for the presence of the privateer but he is saved through the intervention of Yorke and the French refugees.
A hurricane hits the convoy and largely destroys it. Ramage sees Yorke’s ship dismasted and unlikely to survive, he attempts a rescue which results in Triton, herself, being dismasted. Both ships survive the storm though they have lost their small boats as well as masts and spare spars. They drift down on Isla de Culebra, Puerto Rico, and run both ships aground on reefs off shore. Crews from both ships construct rafts and safely remove themselves and most of the ships’ supplies to shore where they establish a base and contemplate how to effect their own rescue.
Isla de Culebra has a small Spanish army garrison which is engaged is a rather strange activity. In time, Ramage develops a plan to capture the garrison and take the ship which delivers their supplies.
They commandeer the ship and use Ramage’s fluency in French and Spanish to evade enemy cruisers and privateers by playing the role of a Spanish coastal merchantman.
Upon arrival in Jamaica, Ramage finds himself under close arrest and charged with an array of capital offenses arising from the battle with the privateer which had entered the convoy. The charges had been filed when it was thought that Triton and Yorke’s ship had foundered in the hurricane. Ramage is confident he can win acquittal, but to do so he must conceal the fact that Yorke and the French refugees survived the hurricane. In the end, Goddard and Croucher are professionally ruined.