Fentanyl was the era’s poster drug. A wonderful medical tool, the hyperpotent synthetic emerged as the underworld’s hyperprofitable heroin substitute. Supplies of it came from China, then from Mexico, as well. Fentanyl upended the dope world the way tech disrupted business. No farmland needed—no pesticides, no harvesting, no seasons, no irrigation. It shrank the heroin supply chain—from dozens of people down to two or three, none of whom were likely to be scary cartel types.
