In the days immediately following Waterloo, the British fleet confronts a new threat: Algerian pirates preying on hapless merchant ships. Adam Bolitho, Admiral Richard Bolitho's nephew and heir, finds himself in command of Unrivalled, a new kind of frigate—sleek, fast, and heavily armed.

Summoned to the Admiralty by Sir Edward Pellew, Captain Adam Bolitho is ordered to sail his 46-gun frigate Unrivalled into African waters to aid His Majesty's campaign against slave-runners. Preoccupied with avenging his uncle Richard's death while confronting an entrenched adversary and the aggressive opposition of the Algerian overlord, he fears he may be setting his crew on a course of doom.

In 1817 every harbor and estuary in Antigua is filled with ghostly ships, superfluous in the aftermath of war. In this uneasy peace, Adam Bolitho is offered the 74-gun Athena, a notoriously "unlucky" ship, and as flag-captain to Vice-Admiral Sir Graham Bethune he once more follows his destiny to the Caribbean.

After the war with France has ended in 1818, Captain Adam Bolitho is given command of the newly commissioned frigate Onward and sent to North Africa on a diplomatic mission to accompany the French frigate Nautilus in a show of solidarity. He knows he is lucky—the voyage should be easy; but Adam longs for a chance to marry the beautiful Lowenna and settle down on the Bolitho estate in Cornwall. Instead he must deal with the envy and ambition of his officers, hidden agendas among his men, and the former enemy’s proximity. Then the Nautilus becomes a sacrificial offering on the altar of Empire, and the hunt is on for a treacherous foe. Suddenly every man must discover for himself whether the brotherhood of the sea can transcend old hatreds and an ocean of blood.

Filled with high-seas intrigue and sharp tensions, this nautical novel takes an intense voyage into the heart of Napoleonic-era Africa. The year is 1819 and Captain Adam Bolitho has been sent on an urgent but risky mission to make a fast passage from Plymouth to Freetown, West Africa, with secret orders for the senior officer stationed there. Due to the slave trade being declared illegal, ships in every harbor are waiting to be scrapped and officers have been cut loose without hope of future commands, thus Adam soon finds himself the object of envy and jealousy. In Africa he discovers unexpected allies and faces an enemy far more powerful and ruthless than any he has known before.