At the edge of the Amazonian jungle, Dr Owen Dawnay has set up an agricultural station. It's a remote place, isolated from the world, and home to a group of half-Indian cattlemen.

Dawnay is puzzled by the cattlemen's apparent fear of the dark. Until he learns of the elusive dwarfs who are supposed to dance among the trees by moonlight. His scientific brain urges him to confront the unknown, but Dawnay has entered a realm of nightmare, one that science cannot explain...