A murder case that happened by mistake implicates several innocent people in a building. A lovelorn woman (played by Karen Mok) was abandoned by her boyfriend on July 15, so she locked herself in her room and kept throwing things downstairs to vent her anger. Two security guards with ulterior motives were also planning to rob the building at this time. A couple suddenly lost their son, so they asked the security captain (played by Lee Lik-chi) for help. The captain entered their home and found another murder case related to the dead old woman. At this time, the lovelorn woman found a mysterious man in black (played by Stephen Chow) standing at the entrance of the corridor and talking to a pot of flowers. The captain discovered that the couple murdered their old mother and was chased. At this time, the ghost of the old mother came to claim her life and was finally subdued by the man in black. The couple was eventually subdued by the man in black and fell to their deaths. The hateful ghost is coming to claim their lives, and several people involved in the incident have no choice but to cooperate with the mysterious man in black...