Chan Kwai-Bun is a brilliant detective who is forced into retirement after presenting his retiring boss with his severed ear. Bun's gift is that he can supposedly see a person's "inner personalities," or hidden ghosts. Years later, Inspector Ho Ka-On is investigating the case of Wong Kwok-Chu, a colleague who went missing when he and his partner, Ko Chi-Wai were in pursuit of a suspect. Wong has been AWOL for 18 months, and his gun has been used in a series of armed robberies. Ho turns to Bun, who now lives in seclusion with his imaginary wife, May Cheung. Bun comes out of retirement and discovers that rather than being one man, Chi-Wai is a seven-spirit collective (with each perhaps representing an aspect of the seven deadly sins with the head, or brain, being a business-like woman. He also discovers that Chi-Wai had his gun stolen by an Indian, named Naresh Sherma, so he killed Wong to steal his gun.