Charles Stépanoff draws on ethnographic literature and his fieldwork in Siberia to reveal the immense contribution to the scope of human imagination made by shamans and the cognitive techniques they developed over the centuries. Northern Shamans travel in mind in ways that appear mysterious to Westerners, but which rely on the human capacity of imagination. They perceive themselves simultaneously in two types of space--one visible, the other invisible--putting them in contact and establishing links with non-human beings in their surroundings. Shamans share their experience of mind travel with their patients, families, or the wider community, allowing them to participate in their odyssey through the invisible. Stépanoff offers an anthropological reflection on the relationships between our uses of the imagination, our relationships with the environment, and the emergence of social hierarchies. This work will appeal to anthropologists as well as to anyone interested in learning about the power of imagination from the masters of the invisible, the shamans of the Far North.