A mob rat and a police mole (Tony Leung and Andy Lau) face off in the 2002 movie subsequently remade as The Wind in the Willows. I mean The Departed.

This Hong Kong cop thriller is like watching someone sprint across a tightrope while juggling torches; a precarious yet precise balancing act between criminal, psychological and emotional elements. The sheer speed is initially confusing – the film is 50 minutes shorter than The Departed, which highlights the difference in pacing between Hong Kong cinema and Martin Scorsese. But directors Alan Mak and Andrew Lau keep all the moving parts in the air with breathtaking skill.

Leung and Lau are grippingly good, given the complex task of playing people who themselves are acting for most of their lives; Leung the undercover cop infiltrating the Triad, Lau the Triad gangster climbing the police ranks. The film depicts the mental strain the decade-long deception takes on the characters, eliciting an emotional response reserved for the best crime flicks.

It shares this classy cat-and-mouse quality with Michael Mann’s Heat – except where Pacino and De Niro were veteran tough guys, Leung and Lau are youngsters pushed to the limits by their superiors. And though these institutions serve opposite sides of the law, their methods are identical. With that moral distinction out the window, it is no wonder these men lose themselves in the process.

Infernal Affairs also still looks stunning (Andrew Lau was cinematographer on Wong Kar-wai’s As Tears Go By) and the Hong Kong style is in full effect, all flashy reflections and rooftop rendezvous. The picture keeps you in its pulse-racing grip as it hurtles towards a Sergio Leone-esque climax, making for a high-wire thriller whose only downside is inadvertently seeding the M. Night Shyamalan movie Split.