Hosted by Tracy Smith. In our cover story, Ben Mankiewicz goes behind the curtain of a new immersive version of the 1939 classic “The Wizard of Oz.” Also: Erin Moriarty investigates the high error rate of urine drug tests that can have devastating consequences; David Pogue sits down with singer Michael Feinstein; Lee Cowan profiles actress Kristin Scott Thomas, who has directed her first film, “My Mother’s Wedding”; Jim Axelrod looks back on late-night TV legend Johnny Carson; and Faith Salie visits two exhibitions devoted to sculptor Louise Nevelson.