He landed a job at a hospital and he soon gets involved in a series of murder cases when his patient murmurs something disturbing.

[4] Cho Jin-woong, who played a doctor suffering a mental breakdown, lost nearly 40 pounds (18 kilograms) for his role in the film.

[7] The film was shot entirely in South Korea, and partially in the Philippines for the ending scene where the teenager met his Filipina mother.

It drew 386,088 viewers on its first day of release, setting the record for the best March opening ever in South Korea.

[8][9][10] The film was sold to Japan, Hong Kong, Macau, the Philippines, and received a limited North American release in the U.S. and Canada.