For years, fentanyl has dominated the opioid crisis in the US — but there’s an up-and-coming class of synthetic opioids emerging called nitazenes, drugs that can be 40 times more potent than fentanyl and far more difficult to track. Now, the investigative group Bellingcat has found nitazenes spreading across the US, and it has discovered links between Chinese suppliers and growing markets in Europe. The World’s Host Carolyn Beeler learns more from Jonathan Moens, the journalist behind the reporting.