The Silenced (2015)
Korea in year 1938. Joo-ran is a talented girl who is transferred to the Gyeongseong Boarding School in the near of Keijyo; the later Seoul. But Gyeongseong School isn't a normal school. The location of the school is kept a secret and even its existence is not known to public, though life seems to be not different from other boarding schools. Joo-ran accidentally learns, that there is another girl who has exactly the same name. She is curious, but the girl disappears right after Joo-ran met her. Now the young girl is confident, that there is something wrong about the Gyeongseong School. Joo-ran starts a risky research to uncover the secrets surrounding the school, which puts her life in danger.