A grizzled detective works to solve the murder of a 16-year-old Hunan girl.

A man lives in a lovely apartment with his wife and 2 children. He is obsessed with cleanliness, has strange dreams and struggles with a mystery in his past. He goes to a bad part of town hunting for a long lost brother, leaving his wife and children in their car. As he tries to get cooperation from neighbors, the wife finds her children are missing. A stranger wearing a dark motorcycle helmet appears, frightening her. As the story unfolds this stranger follows them becoming more and more threatening.