In the remote town of Mompox, Colombia, a mysterious man, known only as El Apredido, "The Learned One," is producing the Devil's Breath, a genetically altered drug that puts its victims in hypnotic states and robs them of their free will and their memory. It has been described by some to have the potential of being the most dangerous drug of all time. Jesuit priest Jack Bennis goes to Mompox at the request of the woman he loves to stop this drug, only to find himself and the woman targets of assassins. When the woman is shot, a twelve-year-old orphan helps Fr. Bennis elude his pursuers in the subterranean tunnels of the ancient Musica people. But when Bennis' sister-in-law and brother, a retired New York City detective, leave Staten Island to come help him, they all become ensnared in a deadly struggle among rivals seeking to use the Devil's Breath for different malevolent purposes which will have worldwide implications.