Captain Hiram Nightingale is a veteran of the wars which have raged throughout Europe and the Americas. But a grand victory at the Battle of the Nile in 1798 comes at a devastating cost. Plagued by wounds both physical and mental, he attempts to recover by accepting command of HMS Scylla. His task is to hunt down a mutinous ship and bring the crew to justice.
However, it soon becomes clear that the mission is just one danger in an immense web. Nightingale finds himself in the middle of a network of secrets that will affect everyone onboard the Scylla. He has to battle against the perils of the war-torn seas, a crew who he fears does not accept him, and meddling, powerful figures from his past.
And in the centre of all this, his new lieutenant, the popular Arthur Courtney, stirs up long repressed feelings. On his journey, Nightingale must confront his own demons. For it seems, during his dangerous adventure, his greatest enemy might just be himself.