After a young woman is battered to death, the mentally retarded Gary Patterson confesses and the police consider the case solved. However, Gary later withdraws his confession, leaving Judge Deed's court struggling with limited evidence.Meanwhile, Deed is also busy looking into a case about a multi-million pound mortgage fraud and comes up against a masonic conspiracy. The fraud case is due to go before a brother judge who himself proves to be implicated, and who commits suicide. In Deed's own court, the jury finds Gary Patterson not guilty, Deed asks who the killer was, and Gary says he witnessed the killing and knows the answer.