From the tide-torn waters of the Thames, where Capt. Nathaniel Drinkwater is compelled to hang a deserter, to the seas off Cape Horn, storm-scoured gateway to the Pacific, the great cruiser Patrician is tense with the threat of mutiny. Despite this, Drinkwater captures a Spanish frigate and meets the stunning Do–a Ana Maria, daughter of the Commandante of San Francisco. But, having disturbed a hornet's nest of colonial intrigue, Drinkwater finds that the Spanish are eager to humiliate him and the Royal Navy. Moreover, a Russian battle-ship lurks somewhere offshore, awaiting Tsar Alexander's dark plans. Caught between two formidable enemies, Drinkwater's mission is made impossible by treachery. Rendered helpless, Patrician is captured, leaving the captain in solitary confinement ashore. But, chance brings the aid of Do–a Ana Maria and a mysterious mountain man. In the distant waters of this beautiful and remote region, Drinkwater struggles to carry out his mission and is struck with the most extraordinary twist of fortune in his eventful life.