Hanson Goodridge is a young, eminent botanist—a plant hunter, who embodies the derring-do spirit of his Victorian and Edwardian counterparts. He is working late in his laboratory at the botanic gardens, studying an extraordinary seed, which has been sent to him anonymously. As he cycles home in the dark, a Barbadian biology student accosts him. She claims to have sent him the seed and explains that it comes from an extremely rare plant, which only grows in Barbados. It is clear from her clandestine behaviour that there is something more sinister behind her actions. Soon after their meeting the girl disappears. Hanson is concerned for her safety. He travels to Barbados in the hope of tracing her and unravelling the mystery, which surrounds this unusual plant.