Dickson Despommier tells us the story of how the insatiable millionaire John D. Rockefeller turned an eye to the untapped market of the American South and ended up eradicating the hookworm (and, in the process, a number of other awful afflictions) with an ingenious contraption. Then Pat Walters introduces us to Jasper Lawrence, a modern-day entrepreneur whose passion for hookworms stems from lifelong battles with allergies and asthma. But unlike Rockefeller, Jasper sees this parasite as friend, not foe.