The supply of fentanyl reaching the US is increasingly arriving from south of the border, supplied by Mexico’s crime cartels.
But this is where it goes, and how it kills, across the United States.
The FBI has announced it arrested 288 people as part of a drive to tackle the illicit trade in fentanyl and opioids, as President Biden called tackling this deadly ‘plague’ one of the priorities of his presidency.
We head to Baltimore to look at the impact of the synthetic drug which is now the biggest killer of Americans aged 18-35 – more than gun crime, more than road accidents.