Synopsis

An ordinary office worker Dong-won (KIM Sung-kyun) and his family move into a house he bought after years of saving. Overwhelmed with happiness, he invites his colleagues to a housewarming party, but heavy overnight rain leads to a gigantic sinkhole, and in a mere minute, it swallows up the entire apartment and the people inside. Hundreds of meters down the hole, Dong-won, his neighbor Man-su (CHA Seoung-won), and the unfortunate housewarming party guests must find their way out. Rain starts to pour down, filling the sinkhole with water, giving them very little time to get back to the surface.