When South Korea is ravaged by a massive demon epidemic that nearly wipes out its entire population, four foreigners are forced to stick together to survive the fallout. After they encounter a Korean survivor who informs them that a nuclear purge of the country is imminent, they realize that escape is the only option. But nothing comes free, and to make it out alive they must overcome their differences and work together to confront not only the flesh-hungry demons waiting for them around every corner, but also the personal demons hiding within themselves.