If we agree that Rear Window, Blowup, The Conversation, and A Short Film About Love belong to the same erotic-thriller subgenre, then this adroit, sexually explicit Glasgow-based tale (2006) of an obsessive surveillance guard (Kate Dickie) tracking and stalking a locksmith and former convict (Tony Curran) qualifies as a minor entry, at least until it becomes an elusive psychological study. Despite the thick Scottish accents, filmmaker Andrea Arnold kept me intrigued, but beyond a certain point the movie’s ambiguity fades into indifference. 113 min.