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.

In 1994, on the first day that Yoo Yeul went on air as the new DJ of the popular radio show ‘Music Album,' a college girl Mi-su meets Hyun-woo who happens to drop by the bakery she works at. Like the music streaming from the radio, their frequencies slowly come in sync; even when they're apart, the show brings them together through ebbs and flows of events arising from both pure coincidence and inevitability, until the bitter reality sets in and drives them apart...