How do officials ferret out smuggled fentanyl – America’s “greatest and most urgent drug threat,” according to the Drug Enforcement Administration? It’s a multifaceted challenge. As Sarah Matusek lays out in detail in our lead story today, it involves the expected: “proactive policing,” education, “the whole of government.” And the unexpected. And, yes, “following the money”: In the IRS office in Denver, a poster reads: “Only an Accountant Could Catch Al Capone.”