Building the mood out of spare parts from westerns and cop movies from the 1970s (the charging score by Mark Mothersbaugh is a distant cousin to David Shire’s work on “The Taking of Pelham One Two Three”), the filmmaker maintains a steady pace of evasion, keeping Luke and Mei on the run as they figure out a master plan of survival, with the ex-cop firing up his protective instincts to ensure that his young charge remains unharmed and her mental parcel is handled with care.