One victim is found dead in his bathtub, but there are also unidentifiable worm-like organisms swimming next to his dead body. The police have trouble understanding the cause of the sudden deaths, as all the victims don't show any physical symptoms but look gruesome as soon as they jump into the water.

Starting with Seoul, dead bodies with similar signs of malnutrition are found every morning in rivers all across the country. While the authorities work to find a cure, Jae-hyuk and his brother Jae-pil ( Kim Dong-wan), a detective who is agonized with guilt for squandering Jae-hyuk's money in the stock market, struggle to save Jae-hyuk's family when they exhibit similar symptoms to the infected. Hence, they jump into the river to allow the worms to come out of the body. Those infected show symptoms of increased hunger without appropriate weight gain and excessive thirst when the worms are mature and ready to reproduce. When a series of dead bodies are found floating in the Han River, the public is shocked to discover that the deaths are related to a fatal outbreak of virus-infected mutant parasitic horsehair worms, called Yeongasi, that can control the human brain. Jae-hyuk ( Kim Myung-min) is a former professor with a doctorate in biochemistry who is currently working as a pharmaceutical sales representative after losing his life savings and his job due to a bad investment he made in the stock market on the advice of his younger brother. Distributed by CJ E&M, the film was released on Jand runs at 109 minutes. The film was directed by Park Jung-woo and produced by Lim Ji-young and Oz One Film. It is Korea's first medical thriller on an infectious disease epidemic (another related film, Flu, was released the next year in 2013). Deranged ( Korean: 연가시 Hanja: 鐵線蟲 RR: Yeongasi) is a 2012 South Korean science fiction thriller film starring Kim Myung-min, Kim Dong-wan, Moon Jung-hee and Lee Ha-nui.

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