People binge eat and suffer from extreme thirst, which leads them to go crazy for water. They cannot control themselves because they are brainwashed by a parasite.
Mr. Kim is jobless, lost in debt and has been dumped by his girlfriend. He decides to end it all by jumping into the Han River - only to find himself washed up on a small, mid-river island. He soon abandons thoughts of suicide or rescue and begins a new life as a castaway. His antics catch the attention of a young woman whose apartment overlooks the river. Her discovery changes both their lives.
A teenage girl is captured by a giant mutated squid-like creature that appears from Seoul's Han River after toxic waste was dumped in it, prompting her family into a frantic search for her.
Under the Sungsan Bridge, in a waterside stand by the Han River, a poor and tired-looking father and daughter, Jae-mun, and In-seon, are arguing the generation gap over whether to buy boiled eggs or instant crackers. The stand owner Hee-bong hears Jae-mun suddenly declare that boiled eggs float.