Intruder

Intruder (침입자, 2020) is a South Korean mystery thriller you can watch online on iFILM. Architect Seo-jin has spent twenty-five years blaming himself for the disappearance of his little sister. Then, out of nowhere, she's found. The family throws its arms around the returned Yoo-jin — but Seo-jin looks at her and sees a stranger.

The warmer his relatives grow toward the newcomer, the harder a single thought gnaws at him: someone who isn't family has walked into the house. His father, his mother, even his small daughter seem to drift out of his orbit, reshaped by her presence. Kim Mu-yeol carries the man from quiet unease into full paranoia, while Song Ji-hyo plays Yoo-jin so carefully that you can't tell until the end — wounded sister, or cold impostor with a plan of her own.

This is the directing debut of novelist Sohn Won-pyung, whose book Almond was a sensation back home, and she builds it like a chamber puzzle: one house, a few people, the ground slowly sliding away underfoot. The final twist splits audiences down the middle, which is exactly its charm. Made for fans of Asian thrillers about switched identities and family dread. Stream Intruder (2020) online on iFILM.