The Wine-Dark Sea by Patrick O'Brian
There is a fine line between privateer and pirate, between friend and foe. With a beleaguered Britain already facing war on two fronts - against Napoleon's armies in Europe but also against the young and vigorous United States - the objective of ship's surgeon and spy Stephen Maturin is to light the touch paper of Peruvian revolutionary fervour, all while Captain Jack Aubrey engages with their many and varied enemies at sea. Will revolution in South America tip the balance Britain's way?