When the United States starship 'Botany' returned from the planet Flora - the Flower Planet - Dr Freda Caron, a cystologist for the bureau of Exotic Plants, stood waiting in the space agency's control tower in the area of touchdown, the San Joaquin Valley. When the officers, scientists, and crew disembarked, however, Freda's fiance, Paul Theaston was not among them. Why had he chosen not to return, almost on the eve of his marriage to Freda? What were the secrets of the Flower Planets? What was its strange hold on Paul? Determined to learn the truth, Freda sets out from Earth to visit Flora - and there, at last, she understands.