A self-styled "accident choreographer", the Brain is a professional hitman who kills his victims by trapping them in well crafted "accidents" that look like unfortunate mishaps but are in fact perfectly staged acts of crime. When he is accosted by a mysterious insurance agent Chan Fong-chow who happened to be on the scene of the "accident" as well, the Brain becomes obsessed that this man must be the mastermind behind a conspiracy to take him out.