James McAvoy undergoes a bold reinvention to become corrupt, alcoholic, drug-adled Detective Sgt. Bruce Robertson in Jon S. Baird’s spirited adaptation of Irvine Welsh’s novel. Vying for a promotion by cracking a vicious murder case, Bruce happily plots to take down his rival officers, while simultaneously juggling numerous addictions, escalating psychotic episodes and a broken family life. Jamie Bell, Eddie Marsan, Imogen Poots and John Sessions head up a strong cast of game co-conspirators, while Baird keeps things moving along at a frantic pace. McAvoy is the real star here, challenging himself to be as outrageous, debauched and disgusting as possible in a fantastically despicable role. While Bruce loses his grip on reality, the film struggles to retain its focus and clarity, but just about holds itself together, albeit it in disheveled, unwieldy fashion.