André Michaux was the most accomplished scientific explorer of North America before Lewis and Clark. His work took him from the Bahamas to Hudson Bay, and it is likely that no contemporary of his had seen as much of the continent. But there is more to his story.

During his decade-long American sojourn, Michaux found himself thrust into the middle of a vast international conspiracy. In 1793, the revolutionary French government conscripted him into its service as a secret agent and tasked him with organizing American frontiersmen to attack Spanish-controlled New Orleans, seize control of Louisiana, and establish an independent republic in the American West. New evidence also strongly implicates Thomas Jefferson in this plot. Drawing on sources buried in the vault of the American Philosophical Society, Patrick Spero offers a bona fide page-turner that sheds new light on an incipient American political climate that fostered reckless diplomatic ventures under the guise of scientific exploration, revealing the air of uncertainty and opportunity that pervaded the early republic.