Although no one had ever followed North American monarch butterflies on their annual southward journey to Mexico and California, in the 1990s there were well-accepted assumptions about the nature and form of the migration. But to Robert Michael Pyle, a naturalist with long experience in monarch conservation, the received wisdom about the butterflies’ long journey just didn’t make sense. In the autumn of 1996 he set out to uncover the facts, to pursue the tide of “cinnamon sailors” on their long, mysterious flight. chronicles Pyle’s 9,000-mile journey to discover firsthand the secrets of the monarchs’ annual migration. Part road trip, part outdoor adventure, and part natural history study, Pyle’s book overturns old theories and provides insights both large and small regarding monarch butterflies, their biology, and their spectacular migratory travels. Since the book’s first publication, its controversial conclusions have been fully confirmed, and monarchs are better understood than ever before. The Afterword for this volume includes not only updated information on the myriad threats to monarch butterflies, but also various efforts under way to ensure the future of the world’s most amazing butterfly migration.