When the courts pitifully low sentencing leaves criminals free to re-offend, justice is certainly not seen to be done. That is until magistrate, victims champion and gin-lover Circe Byrne has had enough of playing by the rules and turns vigilante. Assisted by products from her Lakeland catalogue, the campaign puts a notorious estate in fear and the crime rate drops dramatically. Detective Sergeant Lorcan O'Leary is tasked with finding the cause of the change in criminal behaviour. He is hampered by limited police funding, an irate Assistant Chief Constable, and a father with an exhibitionist form of dementia. The police are very suspicious about the reasons for this unexplained improvement in the figures, whereas local politicians are keen to take all the credit. Circe just manages to keep ahead of the police investigations, but they need to find their vigilante before the serial killer watching her gets there first.