An undercover police officer attempts to take down a drug trafficking syndicate from the inside.
A skilled killer named Shui is forced to retire after a failed mission. He moves into an apartment arranged by the organization. However, unexpected murders start happening in the community. Shui decides to investigate and discovers that the community is concealing a conspiracy — there are hidden killers carrying out missions. Trapped in a dangerous situation, Shui’s only recourse comes from his ordinary neighbors.
