In 1809, Meriwether Lewis, fresh off his famous expedition to explore the Louisiana Territory, is found dead along the Natchez Trace, a dangerous Indian trail in Tennessee. His partner, William Clark, and four members of their 'Corps of Discovery' crisscross the country during the War of 1812 in search of answers. When the war and the investigation collide in New Orleans, the fate of the young nation hangs in the balance!