Alejandro Mayorkas, Department of Homeland Security Secretary says the record number of Americans dying of fentanyl overdoses is the "single greatest challenge we face as a country."

To discuss the rise of the drug, and the impact it is having on people and communities, Kieran was joined by Christopher Booker, special correspondent and producer for PBS NewsHour and WNET in NYC and Sarah Evans, Division Director of Drug Policies, Global Programs of the Open Society Foundations to discuss...