It’s stronger than heroin and more potent than OxyContin. It’s also cheap, ubiquitous, and incredibly deadly. Inside the rise of fentanyl.

Fentanyl: The king of all opiates, and a killer drug crisis, par Jonathon Gatehouse and Nancy Macdonald du Maclean’s

In Montreal, in the summer of 2014, there were at least 25 overdose deaths—six of them in just one week in June—linked to fentanyl-laced heroin.