More than a decade ago, Thomas Kydd and Nicholas Renzi were in the Caribbean as sailors before the mast in the old Trajan. Now Kydd, a storied hero of Trafalgar, holds the glory of being post-captain of the 32-gun frigate, L'Aurore.

After unremitting war a Caribbean posting seems a welcome respite. But Kydd and Renzi soon find themselves facing a familiar threat as the French imperil Britain's vital sugar trade.

When merchantmen begin vanishing from the sea, Kydd and Renzi must embark on a dangerous game of espionage, seamanship and breath-taking action in order to destroy a new and terrible danger to the Empire.