The quest for a bigger and better high has led to the addition of fentanyl, a potent synthetic opiate painkiller, to street heroin. Dealers are giving it out for free to show how potent it is, leaving scores of their customers overdosed and dead in several American cities where it has been reported, notably Detroit and Chicago. Police are conflicted about warning addicts about the dangerous combination for fear of providing free advertising for the dealers. No one knows how the fentanyl has hit the streets or where it comes from. (Washington Post)