Trainspotting author Irvine Welsh created a memorable character in Bruce Robertson, a booze, drug and sex-fuelled Edinburgh policeman whose vileness justifies the title of the book. For writer/director Jon S Baird to cast James McAvoy as Robertson was a considerable leap of faith; McAvoy has a nice-guy persona in films like Wanted and Last King of Scotland that’s the diametric opposite of Robertson. But the casting works; McAvoy is convincingly vental, and his self-destructive tendencies are convincingly wrought. Baird also does a good job in finding a more straight-forward narrative line than in Welsh’s book, even if details like the tapeworm that Robertson converses with are barely realised. Welsh’s prose dares readers to drive through the narrative in search of the next atrocities; whatever its flaws, Baird manages to create the cinematic equivalent, a feverish page-turner that plumbs the depths of a memorable complex and flawed character.