Blood Rain is a South Korean thriller film set in the 1800s during the Joseon dynasty. The story centers on the murder investigation on a remote island where a series of gruesome murders has been happening. Armed with his knowledge of Western science and a rational mind, Won-kyu arrives on the island to uncover the mystery behind the killings.
The investigative process is complicated by the highly superstitious nature of the island's inhabitants who believe that the ghost of a wrongly executed man is behind the killings. Won-kyu soon realizes that the truth is more complex, and the solution to the murders is tied to the island's corrupt ruling elite and a dark past.
As the investigation deepens, Won-kyu finds himself wrestling with his conscience, and his integrity is put to the test as he confronts the harsh reality that justice may not always be served. Blood Rain delves deep into themes of morality, integrity, and the corrupting nature of power. The film is a carefully crafted psychological thriller that highlights the complexities of human nature and the darker aspects of society.