Bafflingly complex but totally assured in tone, style and pace, this adaptation of a celebrated novel by Kaoru Takamura starts out visceral, turns political and winds up metaphysical. The plot conflates a series of seemingly random murders in Tokyo with two dark histories: the fate of a young man orphaned when his parents killed themselves, and the secrets of a college mountaineering club which served as the front for a cell of gay right-wing fanatics. Nakai's down-at-heel detective gives it a very likeable centre. Full of images and scenes which stick in the mind, this is Korean-Japanese director Sai's best film to date.