Hong Kong’s mainstream cinema has generated a flood of unimaginative police thrillers in the last few years, but this oddly engaging 1999 specimen deftly mixes comedy and suspense, cynicism and pathos. Undercover cops Mike (Francis Ng) and Brian (Louis Koo) take up residence in the apartment of a half-crazy old woman in order to stake out a gang of arms dealers in her tenement complex. Mike is brooding and puritanical, Brian is so easygoing that he threatens to give them away, and the woman, whom they nickname Granny, is a loose cannon starved for attention. In one especially tense sequence the cops and their prey are served an impromptu dinner by Granny, who berates them for their bad manners. Each of the heroes gets moony when he’s around his girlfriend, and director Wilson Yip borrows the swish pans, soft focus, and extreme close-ups of Wong Kar-wai’s Chungking Express to suggest the agony and delirium of love. Despite the frequent hilarity, the film bears the stamp of a disillusioned romantic acquainted with life’s bitter ironies.