Osgood and Short are promoters floating stock in a fraudulent tropical rubber plantation among the residents of a New England community. Their best prospect is Elizabeth Mann, a wealthy widow, who is kept from investing only by the influence of her rather effeminate son. To get him out of the way the promoters offer to send him to the tropics to manage the plantation. David, having been brought to a realization of his worthlessness through a curt refusal of marriage, accepts, and is soon landed in the tropics. He meets Senora Morales, a Mexican slave dealer and her daughter, Consuela. They are just departing to deliver a number of slaves to Ludwig Hertzer, the most feared and hated planter on the Isthmus. David gets an insight into Hertzer's peculiar character, and the horror and brutality of the rubber slavery system. Next morning Senora Morales and Consuela arrive with the slaves, among them a big Yaqui chief, to whom Hertzer's half-breed daughter is attracted.