Park Dong Won, a common man, and his family move into a house purchased after 11 years of labor. They throw a housewarming party and invite all their friends. A heavy overnight downpour creates an extremely big sinkhole, and in a mere minute, it engulfs the whole house with the people inside it. Deep down the hole, Park Dong Won, his neighbor Jeong Man Soo, and the guests have to find away out. As the luck would have it rain again begins to pour down, filling the sinkhole with water. They must find out a solution before time runs out to survive.