Donnie Yen is really good in this – a textbook undercover cop movie from Clarence Ford (Naked Killer, The Iceman Cometh), beautifully photographed by Peter Pau and with action scenes which (for the most part) are free from wires. Yen plays a brash, uncouth Hong Kong policeman sent to Nanhai to work undercover with the straight-laced cops on the Mainland – personified by Sally Jing Tian, playing the gifted but cosseted antithesis to Yen’s Cantonese rebel. Of course, in predictable fashion, they eventually bond following the gangland assassination of one of Donnie’s hoodlum chums, and soon they are chasing the baddies together in busted-out cars through the bustling metropolis of modern China. The film culminates in one of the best in-car fight scenes and a blistering MMA encounter between Donnie Yen and Andy On which is one of Yen’s best finales for a long time. Despite occasional lapses into mawkish wholesomeness, on the whole the film remains tense, gritty and entertaining throughout.