Door Lock

Kyung-min is a single bank employee who lives by herself in a small studio apartment. When she notices signs that someone has been entering her home without permission, she reports it, but the authorities see no reason for alarm. Her unease grows after an unsettling encounter at work, and before long a murder case becomes tied to her own apartment. The film follows her attempts to work out who has been getting in and why, while those around her question whether the danger is real.

Door Lock is a 2018 Korean crime and mystery thriller directed by Lee Kwon, who wrote the screenplay with Park Jeong-hui. It was produced by Yi Jae-min for Plus M Entertainment and Studio Pieona. Kong Hyo-jin plays Jo Kyeong-min, with Kim Ye-won, Kim Sung-oh, Jo Bok-rae, Lee Ga-sub and Lee Chun-hee among the credited cast of 21. The film was made for about 3 million USD and took roughly 11 million USD worldwide, a strong return relative to its cost.

Audiences rate it at 6.4 out of 10 on IMDb from around 4,400 votes, while TMDB users give it 7.4 out of 10 from a much smaller group of 177. The gap suggests a modest but real following rather than broad acclaim.