War at sea: While Matthew Hervey is getting ready to re-join his regiment in England, his close friend Captain Peto is at sea preparing his mighty line-of-battle ship for war with the Turks.

1827: Captain Peto has just taken command of HMS Prince Rupert, the only three-decker line-of-battle ship in His Majesty's Fleet — a wooden fortress whose formidable firepower is the equal and more of Bonaparte's grand battery at Waterloo. But his journey to the Aegian, where Admiral Codrington's flagship awaits him, will not be smooth sailing, having as he does, a largely inexperienced crew. He's also been entrusted with the safe passage to Malta of the Admiral's youngest daughter — a situation that is far from ideal for Peto and his crew.

A year on, and Hervey is in London recovering from a recent bout of malaria. All is set fair for his upcoming marriage, and his subsequent return to active duty in the Cape. But trouble lies ahead as family commitments clash with affairs of the heart, and Hervey finds himself embroiled in a military enquiry that could result in public humiliation.

As the cataclysmic sea-battle of Navarino Bay looms ever closer for Peto and his crew, Hervey faces a regimental crisis that may be beyond even his capabilities.