Kim Ji-yong leads a double life as a Korean National Police University student by day and the Vigilante by night, personally punishing criminals who evade the law. He is surrounded by people who all possess different ulterior motives.

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.

A grumpy old woman befriends a young civil servant and learns English from him. She then reveals to him her shocking past.

A team of tenacious detectives study the minds of murderers at a time when Korea's first serial murders terrorized the nation. Based on true events.