The undercover cop story is a staple in Hong Kong cinema, and Derek Yee works hard to impart a new spin on this mob procedural.
He finds few fresh insights in Daniel Wu’s relationships with drug baron Lau or junkie neighbour Zhang Jingchu and her toddler daughter, although there are moments of bruising action to compensate for the domestic melodramatics.
The forensic detail Yee provides on the mechanics of the heroin trade is absolutely fascinating, with a trip to the Golden Triangle in Thailand given extra spice by the fact that Lau has let his guard down following a botched customs raid that should have exposed Wu’s treachery.