Death Bell (Gosa)
At an elite school in Seoul, test scores and parents' social status are everything. When the best students are gathered for a special study session, the terror begins: one by one they disappear and die in horrific ways, broadcast on CCTV. A mysterious voice on the speaker warns that anyone who tries to escape will die, while posing a puzzle that must be solved. Teacher Kim leads the rescue effort, but can they uncover the pattern behind the killings—or is it perhaps not human? Who will survive?