Betting on War; The Knowledge; Christopher Nolan

S58 E24

Choke Point; Laser Focus; Growing Up Behind Walls

S58 E25

Elemental Crisis; Turning the Ship Around; The Dog Aging Project

S58 E26

Inside the Tower; Unmanned; Wonder of the World

First, investigating the D.C. midair plane crash. Then, a look at the drone arms race transforming modern warfare. And, inside Son Doong, the world's largest cave passage.

S58 E27

Return to RAM; Ghost Train; The Mardi Gras Indians

First, a report on patients, cut off from health care, getting help. Then, the state of high-speed rail in the U.S. And, a look at the Mardi Gras Indians keeping tradition alive.