Upon launch, Juul rolls out an edgy campaign targeting youth culture until the popular ads come under criticism and spur new regulations from the FDA.

Viral social media videos and word-of-mouth send Juul and its flavor pods flying off shelves — and into the hands of kids, causing nationwide outrage.

A landmark deal makes billionaires of Juul's founders but leaves other employees torn. A health crisis linked to vaping jeopardizes the company's future.