On a cold afternoon in February 1991, a frightening new drug hit the streets of New York City, a synthetic narcotic marketed in packets labeled "Tango & Cash." As police scrambled to warn heroin users of the danger, the overdose victims began piling up in hospital emergency rooms and county morgues across three states. As a Drug Enforcement Administration agent said at the time, "We don't know yet who's putting this stuff out there, but whoever he is, he's an ice-cold son of a bitch." Fentanyl had come to America. In 2024, fentanyl is killing nearly 200 Americans every day, a seemingly unstoppable narcotic curse like none ever seen before. But few know that this plague began in the brilliant mind of the high-school dropout and chemistry prodigy that the DEA called "the best and most dangerous clandestine chemist" it has ever encountered. The clandestine chemist was George Erik Marquardt. Starting at just twelve years old, Marquardt used his extraordinary talents to make every illegal drug in the book, from bootleg booze to heroin. He brewed LSD for Timothy Leary and the Grateful Dead, methamphetamine for outlaw motorcycle gangs, nerve gas for Idaho Nazis, and even life-saving AZT for AIDS patients. But when that ice-cold son of a bitch turned to fentanyl, thousands of Americans would die. In LETHAL DOSES: The Man Who Gave Fentanyl to America, award-winning author and former undercover agent for the Oklahoma Bureau of Narcotics John Madinger, tells the remarkable story of DEA's three-year pursuit, the genesis of our fentanyl problem today, and the uniquely dangerous evil genius he spent hundreds of hours interviewing.