Jeb, a lecturer at Harvard, meets a mysterious pilot with a map who is murdered, the eyes sucked out of his skull while he is still alive. Jeb, shaken by the horror and wanting no more of it, is asked by the faculty at Harvard to travel to Colombia in search of ancient emeralds. In an Indian dialect, the map tells of their secret location. A Monster guards this secret for which the eyes of humans are sacrificed. General Junco, his contact person, finds refuge with an obscure woman, while his red-headed wife Lourdes, once a great beauty, is served nightly by a shadow lover. Jeb is provided a house in which to live with a housekeeper, Lucy, who remains strangely distant. His lady back home, Courtney, teaches at Sarah Lawrence. Lola, the beautiful secretary of General Junco, commands his attention, providing a momentary distraction from the horror that awaits him. An assassin has been sent to Colombia by Geneva emerald dealers, who, though leaving many bodies, is never seen. Jeb guesses the source of the Monster's emeralds, a dark rainforest where Indians have been tortured for centuries, and again enslaved and murdered during the nineteen hundreds by the rubber barons, a horror called the Devil's Paradise. Lucy, the housekeeper, follows him. She is caught by thugs and deposited among the rotting corpses to await the sucking out of her eyes. From nowhere, the unseen assassin appears and frees her. She finds Jeb in the rainforest and together they elude the Monster, escape warring Indians, the descendants of those who were tortured, survive an electric eel, avoid the drug lords, and finally fall through the ground into a cave filled with skeletons, and gold-and-emerald artifacts, from which there appears to be no escape. Only after a cruel twist of fate is the shocking truth of this green horror revealed.