As the War of 1812 rages, Marcel Moreau, wounded in service with Napoleon's Grand Armée, must journey to New Orleans to find Celeste de Beaumais, a young aristocrat who has fled her family and has settled herself on a sprawling Louisiana plantation. Standing in Moreau's way are various factions in and around the city—soldiers, slave hunters, marooned slaves, and Baratarian pirates—all of whom have their own interests, and enemies. As he ventures deeper into the city and the vast cypress swamps beyond, Moreau will find that circumstances are much more complex—and dangerous—than he could have imagined.

Meanwhile, a massive English fleet looms on the horizon, causing panic in New Orleans and desperation from the outgunned and outnumbered Louisiana militia. Hoping to benefit from his years of experience with Napoleon's Grande Armée, these French-speaking creole farmers and townsfolk, and their American allies, enlist Moreau to help train them for the coming fight. As he does what he can to help this motley fighting force, Moreau soon comes up against another enemy. With the city's eyes on the battlefield, a ruthless plantation master plots his own designs. But those who've escaped his clutches have no plans to return to a life in chains, and Moreau must decide where his experience and instincts must be put to the best use.