A monter emerges from Seoul's Han River and focuses its attention on attacking people. One victim's loving family does what it can to rescue her from its clutches.
The film revolves around Park Hee-bong, a man in his late 60s. He run a small snack bar on the banks of the Han River and lives with his two son, one daughter, and one granddaughter. The Parks seem to lead a quite ordinary and peaceful life, but maybe they are a bit poorer than the average Seoulite. Hee-bong's elder son Gang-du is an immature and incompetent man in his 40s, whose wife left home long ago. Nam-il is the youngest son, an unemployed grumbler, and daughter Nam-joo is an archery medalist and member of the national team. One day, an unidentified monter suddenly appear from the depths of the Han River and spreads panic and death, and Gang-du's daughter Hyun-seo is carried off by the monter and disappear. All of the family member are in a great agony because they lost someone very dear to them. But when they find out she is still alive, they resolve to save her.

condo ( decorated with Song Kang-ho ) is an early death of his wife 's middle - aged man, leaning against the Han River near the business shop daughter Yuen Shu ( elegant as ornaments ) to raise , to live with them , father Hee peak ( Hee peak decorated ), sister decorated pearl ( Bae Doo Na ) and brother South ( Park Hae ornaments), the family of a five three generations under one roof , but far less harmonious than most people imagine , daughter of Yuen Shu quiet at home , always stood a cold face , my brother Nanri home only college students , you can always feel underappreciated , motionless grumble , and even parents to participate niece Yuen Shu is the most Xunxun 's . The only good point is the sister of pearl , has chosen a tomboy , neither gentle nor virtuous , how is not a big girl . In this family, everyone living in their own way , familiar and strange , monotonous and lack of vitality , are their life to live like this ? Accidental condo with her daughter to spread the edge of the Han River somehow gathered a lot of people , curious , they ran over to watch , they see in the Han River Bridge pier tightly clings to a never seen before creatures, people are constantly facing this thing talking about . The crowd finds fault with this monster when the monster suddenly channeling ashore and launched an attack like the crowd . Monster casually biting condo decided to immediately fled the scene with her daughter , condo in confusion lost contact with her daughter , her daughter was a terrible monster away . Condo home dejected he can not face the eyes of family responsibility , will not be able to get rid of the torment of his soul , asking for help to save his lovely daughter , but the entire city into a panic , activities have all been canceled , no one wants near the Han River . no one wants to lend a helping hand to the family of this weak , if you want to save the daughter of Yuen Shu only by members of this family , they can unite to do ? Rely on their own meager power they can rescue their loved ones ?