1906. Three young Englishmen, Bob Wilmot, Patrick McDiarmid and our narrator, Richard Langley, are recruited by Ula Valdien, a mysteriously beautiful woman. Ula asserts she is a wrongfully-exiled heir to the throne of the Valdi, a lost kingdom of South Americans who were also descendants of Atlantis survivors. They are really the Amazons, and a rival group overthrew Ula, exiling her as the rightful Queen-Empress. Following a long and harrowing voyage over sea and jungle, they reach the ancient and secret land of the Valdi. They are greeted by Lady Valma, the current ruler, who tells Bob and Richard the true story behind Ula's exile. They discover that Ula is the champion of an evil religion that practices human sacrifice. Bob and Richard believe Valma and become her allies, however, Patrick is so in love with Ula that he cannot see her true nature. Will Ula or Valma reign victorious? Illustrated.