Korean horror co-written and directed by Joon-Ho Bong. The film follows snack bar owner Gang-du Park (Kang-Ho Song) and his family as they are forced to fight back against a mysterious monster which emerges from the Han River in Seoul. Fearing the worst after his daughter Hyun-seo (Ko Asung) is captured and carried away by the unidentified creature, Gang-du is left shocked when he receives a phone call from her explaining she is being held captive by the monster deep in the sewers. Spurred on by Hyun-seo's unexpected call, Gang-du gathers together the remaining members of his family and bravely sets off into the sewers in a bid to rescue her.