You can't really blame Cheng Lai-sheung (Josie Ho) for killing people in her effort to obtain the title dwelling of Edmond Pang Ho-Cheung's erratic thriller, a flat in a high-rise in Hong Kong's posh Victoria Harbor. First, there's the impossible real-estate situation in the densely populated city. Then there's her own background — growing up in a poor neighborhood harassed by property developers, her father ill, her younger brother dependent, her job as a telemarketer inadequate. Finally, there are the victims: despicable for the most part, selfish, depraved, materialistic. Still, there are limits to justified sadism. Pang ambitiously wraps a slasher flick with an emphasis on asphyxiation and sexual humiliation around a critique of Hong Kong society. The carnage is excruciating and sometimes funny, and the quiet rage of Ho's heroine is almost comprehensible. But the flashback format is clumsy and confusing, and the violence veers toward the misogynistic.