Is violence a virus? Can your genes make you a killer? Why are we so willing to hurt each other? In *The Babel Effect*, the brilliant husband-and-wife research team of Ryan and Jessamine McCloud are charged with answering these urgent questions. Beginning as a neurological study of murderers on death row, their research explodes into an investigation into the biomedical foundations of human history. The quest takes them from prison cells to research labs to war zones throughout the world and forces them to doubt their most basic assumptions about the human species, about themselves, and about their marriage. Combining systems theory with modern epidemiology, they soon learn that our propensity for violence resembles a contagious disease. But is the human carnage of the last hundred years an ancient plague or a new nightmare? Can they identify the cause and find a cure? As their discoveries reveal frightening secrets about multinational corporations, clandestine military programs, and millennial religious cults, they realize that finding the answers depends on a still more urgent and terrifying question: Can they survive the search? When an unknown enemy steals their data and abducts Jessamine, the FBI investigation stalls, and Ryan realizes that it is up to him alone to find his pregnant wife. He soon finds that to learn where she is, he must discover who she is -- and confront the question of whether we can ever really know the one we love.