It is, by any measure, an epidemic. Heroin is not new or chic, but its use and abuse are spiking. According to data from the CDC and the National Center for Health Statistics, heroin-overdose deaths rose gradually from 2000 to ’10 but then almost tripled in the following three years to 2.7 deaths per 100,000 people. Heroin use cuts across demographics. Public authorities devoted to prevention and law enforcement, from the DEA to the CDC, have been struck by a growing concentration in an unlikely subset of users: young athletes. Here, Wertheim and Rodriguez discuss how painkillers are turning young athletes into heroin addicts.