Jack Aubrey and Stephen Maturin--the amiable, music-loving heroes of O'Brian's wonderful sail-powered series (The Truelove, The Letter of Marque, The Far Side of the World, et al.)--follow orders into the midst of revolutionary South American politics. His Majesty's government has become interested in Peru, where the Spanish vicegerency is tottering and the beastly French seek greater influence. Who better to send to see that, when the old order falls, the new government is Anglophilic than that extremely clever half-Spanish ship's surgeon and spy Stephen Maturin? Maturin, concert-quality cellist, and Captain Jack Aubrey, the best violinist ever to command a man-o'-war, have successfully concluded their business in the South Pacific and are on board Surprise, a privateer. Licensed to steal anything they find in the way of enemy shipping, the duo make it a profitable crossing, taking their biggest haul from the Yankee ship Franklin, which carries, in addition to tons of loot, one Monsieur Dutourd, who says he's just another string-player and utopian disciple of Rousseau but who seems entirely too interested in Peruvian politics. Dutourd presents a problem in that he and Maturin have crossed paths in Paris, and if they land in Lima together, Maturin's identity as a British spy may become known. Along with fretting about Dutourd, Dr. Maturin is concerned about his assistant and fellow naturalist the Rev. Mr. Martin, whose belief that lust in one's heart can result in venereal disease has brought him to death's door. When the sailors at last reach the shores of Peru, Dutourd escapes and Maturin's mission, complicated enough by the various revolutionary factions, becomes a real hair-raiser involving an arduous transit of the Andes, where he is spit on by llamas and sees the great condors. Literate, leisurely, and as charming as the rest of the series. The illustrated guide to sails and masts is worth the price by itself.