Five months after the events of the first series, DS Marcella Backland (Anna Friel) is called to a house where a body has been found. She is shocked to discover that she knew the victim - a 9-year-old boy, Leo Priestley, who disappeared four years ago after agreeing to walk home with her son. A convicted paedophile; an aging Rockstar and his agent; a self-made millionaire and his wife, the founder of a successful children's charity; and a veteran of Afghanistan struggling to support his sister and her baby are soon all on the investigating team's radar. Even relatives and colleagues fall under suspicion. Meanwhile Marcella is finding it harder and harder to keep her violent fugues under control and her therapist suggests that the only way she can be rid of them is to revisit their source - the painful loss of her baby by submitting herself to hypnosis.