Napoleon Bonaparte's ambitions for world domination are growing apace, and when Captain Sir Thomas Kydd returns to take up command of his ship Tyger, he finds himself called to be part of a great armada on a mission of the utmost urgency. Unbeknownst to Kydd, his old friend, Renzi, has been called upon to undertake a parallel diplomatic mission. Kydd is captured by the French but in a strange twist finds himself released to snatch the future king of France from exile. He returns to find a scene of chaos and terror.