Refusing to shy away from nearly unutterable emotions, the forceful new film from Kenneth Lonergan, Manchester by the Sea, follows a troubled Massachusetts handyman (an unforgettable Casey Affleck) who travels to his North Shore hometown after the death of his brother and must confront memories of an earlier tragedy. As proven in You Can Count on Me and Margaret, few American filmmakers today are better at making movies that express how difficult it is to move on from the past.