Tactical Unit III -Partners is the concluding story of the five-part-series of Tactical Unit produced by the renowned Hong Kong director Johnnie To. Lawrence Lau continues to be the director of this film after he filmed No Way Out, the second part of the series. This film continues featuring original PTU casts Simon Yam, Maggie Shiu and Lam Suet, together with other casts young icons Tsui Tin-yau, EO2 Otto Wong and Osman Hung, and other veterans Tang Ho-kwong and Sino-Indian Singh Hartihan. A rumor goes that the long disappeared Indian gang boss nicknamed "Black Molly" has returned to regain his past glory. PTU surgeons Jim (Simon Yam) and May (Maggie Shiu) face challenges from these fierce East-Asian criminals apart from local triad members. Velu is a Sino-Indian and once a no-fear gang member under “Black Molly”. He was put behind bars because of a triad mission and his younger brother was shot dead by Sam in the mission. After finished serving his sentences, Velu has decided to leave his gang, but his departure makes his good friend Sonu feels being betrayed. Meanwhile, Sonu is assigned an assassination mission to kill Sam and May's superior, Chief Inspector Chan...