It’s no secret that the people of North Korea suffer privation, brainwashing and systemic abuse, all in the name of providing its vicious ruling dynasty with nuclear weapons to rattle. Madeleine Gavin’s brave documentary shines a light behind the curtain and shows just how bad conditions are.

But this compelling, urgent film is not about geopolitics, focusing instead on the nail-biting escapes of those seeking a better life. It centers on South Korean pastor Seungeun Kim, who not only supplies would-be defectors with information and advice, but repeatedly puts his own life on the line by personally accompanying his charges on their harrowing journeys. The guy’s a saint by anyone’s standards, even us athiests.

Gavin is also along to film, often apparently with iPhones, the tense, labyrinthine escape through several countries attempted by the Ro family, including little kids and an 80-year-old grandmother. Watch their unbelieving reactions to life in comparative paradises like Vietnam. Not a frame is recreated. It’s a bit clunky in spots, and the score is trite, but these are nits in light of its importance and bravery. Once seen, though, it’s impossible to un-see. And that’s as it should be. (115 min)