The nineteenth century dawns and the Napoleonic Wars rage as Horatio Hornblower is ordered to the Caribbean and dangerous waters. New Lieutenant Hornblower's latest ship is HMS Renown, a sound vessel whose captain is unfortunately of rather unsound mind. When ordered to attack a Spanish anchorage, the chain of command breaks down and it requires all of Hornblower's seafaring cunning to avert disaster. As cannons pound and splinters fly aboard their beleaguered vessel, and the men are forced to engage at close quarters, the young lieutenant knows that to save his ship and crew he must prove himself a master of the high seas.