Infernal Affairs II

A loose prequel to 2002's hit Infernal Affairs, this goes back to the 1980s and '90s when the Hong Kong police force and the city's ruling triad sent undercover agents into each other's organisations.

Tony Leung and Andy Lau are missed as the supermoles (played here by young look-alikes) but directors Andrew Lau and Alan Mak have something smart up their sleeves, shifting the emphasis of the story onto the able shoulders of the pair's world-weary veteran superiors. Anthony Wong and Eric Tsang are excellent as the morally compromised cop and likable but capable capo, ageing friends who understand they stand just over the line from each other.

A knowledge of the first film helps navigate the labyrinthine plots of the dizzying opening act but once it finds its pace, it's a slick, slow-burning thriller all the way – marred only by the directors' occasional lapse into Godfather pretensions – while the backdrop of 1997's hand-over of Hong Kong is effective shorthand for the huge changes taking place within the forces of both law and disorder.