Property agent Wei (River Huang) lives with his grandmother (Liu Yin-shang), but one day she suddenly disappears without a reason, and yet the routines of the house still continues as usual - the laundry is done, the house is well-cleaned as usual and even Wei's breakfast remains prepared every morning. A clueless Wei then starts to search for his grandmother until he finds an uncanny video in his neighbour's camera, where a little girl in red was tagging behind his grandmother while she was hiking. Oddly enough, after Wei's grandmother finally returned, Wei went missing instead. Wei's radio DJ girlfriend, Yi-chun (Hsu Wei-ning) gradually discovers that all these mysteries might be connected to the urban legend "The Little Girl in Red" and that the worst is yet to come.