This series contains mature themes and depictions of bullying, self harm and suicide, and graphic violence. Viewer discretion is advised. In a twist and turn of events during a school trip to a rural, northernmost province of South Korea, Se-yeon and her classmates find themselves stranded on a remote island off the coast of North Korea. Extreme circumstances drive the youngsters to take extreme measures to survive. Who will live on, and who will fall victim to the harsh reality surrounding them?