The brief respite of the Peace of Amiens is over, and Britain is once again at war with France. Napoléon knows that if he is to win the war, he must invade England, but the Armée d’Angleterre is blockaded in Boulogne by the Royal Navy. Frustrated by British sea power, Napoléon entrusts an alternative scheme to the brilliant Captain Morlaix which if successful, could lead to the subjugation of Britain.
During the Peace, English visitors had flocked to France, among them Midshipmen Stone and Snowden. At a soiree in Paris, they attracted the attention of Fouché, the feared minister of police, who believed that Jack Stone was a civilian when he fought the French in Normandy, and is therefore a criminal.
In the subsequent war, Lieutenant Snowden leads a raid to disrupt France's invasion plans.