The world has been reduced to rubble by a massive earthquake. While no one knows for sure how far the ruins stretch, or what the cause of the earthquake may be, in the heart of Seoul there is only one apartment building left standing. It is called Hwang Gung Apartments. As time passes, outsiders start coming in to Hwang Gung Apartments trying to escape the extreme cold. Before long, the apartment residents are unable to cope with the increasing numbers. Feeling a threat to their very survival, the residents enact a special measure.
While investigating a terroristic threat that goes viral online, Korean authorities discover that a suspect has recently boarded an international flight bound for the United States. When a healthy passenger on the same flight suddenly dies a gruesome death of unknown cause, panic erupts both in-flight and on the ground. With steadily decreasing fuel and international refusals to offer aid, the captain and crew will be forced to take unprecedented emergency measures in an attempt to save the lives of their passengers.