In the winter of 1803, one woman stands between Napoleon and the fall of Great Britain The free-spirited daughter of an English baronet, Lisbeth defies convention by eloping to France. When her husband abandons her, she must find a way to survive and be reunited with her young son, who is in the care of her mother-in-law. A seasoned spy known as Tidewatcher, Duncan apprenticed under Lisbeth's father and pledged to keep his mentor's pretty daughter safe—a promise complicated by the wily Napoleon Bonaparte. The British believe he is planning an attack, and Duncan is sent to search for signs of invasion on the French coast—where he draws dangerously close to adventurous and unpredictable Lisbeth. A sensational new invention may shift the tide of a French victory. A brilliant and eccentric American inventor named Robert Fulton has devised a deadly weapon that can decimate an enemy's fleet. To protect English ships, Tidewatcher must gain control of Fulton's invention and cross enemy lines . . . but he cannot do it alone. Left with no other options, he enlists Lisbeth's help in outwitting the American inventor and uncovering Bonaparte's secret plans. Going undercover for the handsome and duty-bound spy, Lisbeth risks her freedom and her life as she navigates double agents and submarine warfare to outwit the greatest military tactician in history. The only question is . . . who can she trust?

When saving your country from invasion isn’t enough… On the eve of war, British diplomats burn the names and missions of their agents on the sands of Boulogne-sur-Mer, France. Two papers escape, seemingly by chance. Soon French and British bounty hunters chase all three Stewart brothers. The only way to protect their family is to give in to the most official form of blackmail. Duncan and Lisbeth begin a deadly assignment to discover the double agent in the British Admiralty, while Cal and Alec join the Paris Underground, with Britain’s top real-life spies: Mouron, The Pimpernel; and The Incomparable, the beautiful woman who can out-think most men. But not all men, all the time – especially not one who knows her past. From the wilds of Scotland and Wales to the glittering Winter Palace at St. Petersburg, from the Paris Underground to the deceptive peace of Portsmouth and the world’s first death camp, the Stewart brothers and Lisbeth are pushing back a tide they can’t even see. And the consequences of success are almost worse than failure.