Having recently split up from the father of her baby, Lilly is not in a happy place, matters being complicated further by the arrival of her ex-husband, needing a sofa to crash out on having been thrown out by his girlfriend. In the midst of all this Lilly is asked by a child psychologist if she will help one of her patients: a girl currently sectioned having stolen a car while extremely drunk. While Lilly visits her she is introduced to Chloe, another unstable teenager who slips Lilly a note saying: 'Help us'. And then Lilly's client is killed and Chloe accused of her murder. Her case is not helped by the fact that the words 'Help us' have been carved on the dead girl's stomach ...