A new documentary by The New York Times traces the e-cigarette maker on its path from fledgling start-up to Silicon Valley juggernaut and, eventually, public health villain. Adam Bowen and James Monsees, by their own telling, set out to improve the lives of a billion people by getting them off cigarettes.

But somewhere on the path from fledgling start-up to Silicon Valley juggernaut, their company, Juul, went tragically off course. Instead of upending Big Tobacco and hastening the end of smoking, Juul’s flavored e-cigarettes became a popular on-ramp for a new generation of nicotine addicts.