Portraits of the former North Korean leaders hang overhead as the escape plan rumbles into motion. The would-be defectors move toward the border, where they struggle to deactivate lasers that would alert guards to their presence. Bullets whiz by as they ford through the icy waters of a narrow river crossing.

Their journey follows the path to freedom that thousands of DPRK refugees have taken in recent decades — except for a key difference: Those fleeing are South Koreans, and they’re escaping a shipping container in the middle of Seoul.