
A self-styled accident choreographer, Brain (Louis Koo) is a professional hit man 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. He is perennially plagued with guilt, as the avalanche of memories of his lost wife does not make things any easier.
After one mission inexplicably goes wrong, costing the life of one of his men, Brain becomes convinced that this accident has been choreographed: someone is out there plotting to terminate him and his team. He becomes increasingly paranoid, not knowing whether or not to trust his friends and accomplices.