Denis (Jonny Lee Miller) is a man whose life is shattered by a single criminal act in which his young wife is killed in a bungled break-in by a psychotic career criminal Ricky Barnes (Serkis). Denis, for whom life up to then had seemed perfect, cannot cope with his loss, and dedicates his life to tracking down the man responsible. It is a pursuit which requires him not only to be sent to jail, but to be sent to the worst prison in Britain...