Joe Miller (Matthew Macfadyen) is a barrister at the height of his professional powers. He is married to Juliet (Maxine Peake) who is fragile and isolated at home with her 13-year-old daughter Ella. When one night Juliet stabs Joe in their bed, she sets in motion a chain of events as hard and unbreakable as any the law can offer.

As she travels through the criminal justice system under the constant scrutiny of police, prison officials and social services, her guilt isn't questioned, but her motives are. As the case passes through family court towards a tense and unpredictable finale in the Crown Court, the terrifying blunt force of criminal justice is felt from the moment it is called into play right through to its terrible execution.