Hong Kong superstar Andy Lau puts on a prosthetic body again for co-directors Johnny To and Wai Ka-fai, who also made the romantic comedy Love on a Diet, in which Lau wore a fat suit. In Running on Karma, Lau plays an enormous bodybuilder, and while this is a more serious film, the filmmakers use the dissonance of seeing Lau's head atop that hulking (often nearly naked) body to great comic effect. In fact, the opening sequence, in which Lau is entrapped by a comely undercover cop (the adorable Cecilia Cheung) into stripping completely nude, while the cops upstairs discover a contortionist killer who can fit himself into an oil can, is startling -- both comic and horrific -- in its strangeness. There's a level of inventiveness to the setup (Lau as a stripper/superhero/chain-smoker/former Buddhist monk who can "see" karma) that the film can't sustain, and the story line involving that creepy killer is resolved disappointingly quickly. But Running on Karma remains a singularly intriguing whatsit, a sometimes gruesome thriller/revenge drama/romance with deep spiritual underpinnings (as when Lau's character confronts what he might have become, had he chosen a darker path) and genuinely funny comic moments (as when, over dinner, Lau and Cheung discuss the previous life of the chicken they're eating). The film offers ample evidence that there's plenty of life left in Hong Kong genre cinema.