It is 1814 and Napoleon has abdicated as Emperor of the French. King Louis XVIII is brought out of his English exile and escorted back to France by an Allied squadron commanded by the Duke of Clarence. The 'Great War' is at en end and Europe prepares to celebrate the return of legitimate monarchy.
Attending King Louis, Captain Nathaniel Drinkwater is alarmed to receive secret intelligence that a new and imminent threat exists to peace.