A look at the SDU in the Royal Hong Kong Police Force - how members are selected, how they are trained, their lives, what they think, the relationships between SDU members and their friends and the pressures they face.

Chan Wai (Simon Yam) is a former inner-city policeman recovering from a traumatic experience involving an AK-47. After the incident, he was assigned to a rural island as police chief of a small village. He passes his uneventful days there drinking beer, smoking hash and daydreaming... but when a group of heavily armed thugs invade his district, he must face his trauma head-on and fight back.

In this prequel to the original, a bloody power struggle among the Triads coincides with the 1997 handover of Hong Kong, setting up the events of the first film.