APT (released as 9:56 in Singapore) is a 2006 South Korean horror film, directed by Ahn Byeong-ki and starring Ko So-young. It is based on a comic by Kang Full.

Plot summary

Se-jin, a lonely department store employee, moves into a high-rise apartment building. One day she notices that the lights in the windows of the building opposite all start to mysteriously flicker at exactly 9:56pm. She begins to suspect that these occurrences are somehow linked to a series of suspicious deaths in the neighbourhood.

Cast

• Ko So-young ... Oh Se-jin
• Kang Seong-jin ... Detective Yang Na-sun
• Jang Hee-jin ... Yu-jeon
• Park Ha-seon ... Jung-hong
• Yoo Min ... suicidal woman at the subway
• Kim Gyoo-min