Clive Reader is celebrating his successful conviction of a client, but Martha, the chambers head's wife, is furious with the inspector Wright for lying in court. She believes that her husband has been wrongly accused and wants him to intervene in her son David's case. Meanwhile, David, the teenage son of Alan Cowdrey, is arrested for the death of a policeman during a demonstration. Martha suspects that David was bullied into pleading guilty by Wright and wants Alan involved in the case. However, David is not keen on seeing his father involved. Reader and Caroline Warwick agree to help Martha out, who sees on CCTV that an anonymous man spoke to David in custody but there is no record of this meeting. In court, Martha faces Wright again, determined to win her case. She discovers new evidence that weakens Wright's case and changes the outcome of her crusade.