The body of a young woman is found who'd been murdered using electrocution. Then the body of another young woman is found who'd been murdered in the same way and she's the daughter of a prominent Manchester prosecution lawyer.
A suspect linked to both women is quickly identified by Chief Constable Ronald Hermitage who tries to bounce Barton into charging the man before enough evidence is gathered. Hermitage has a personal score to settle with Barton and uses it to try and force his will. But Barton resists and when the body of another young woman is found that the suspect could not have had anything to do with, Barton gains the upper hand in trying to catch a brutal and viscous killer.
Using the knowledge and experiences of his two new team members he brings to light a pattern of sexual abuse of young girls that's connected to the group of corrupt police officers and their associates known as the circuit. And Chief Constable Ronald Hermitage is right in the middle of it.
Barton and his team realise that someone is taking out revenge for the crimes of the past. But who is doing it and why have they waited until now? He manages to bring down the circuit but will a determined killer who's full of vengeance be as easy?