Following Catherine's visit to the house Royce moves Ann but the van in which he and Lewis are taking her is stopped for speeding by policewoman Kirsten McAskill and so Royce, to Lewis's horror, runs Kirsten over, killing her. Reminded of her daughter's death and accused by Kirsten's partner of pushing her into action Catherine is devastated and, whilst Richard offers to accept Ryan, she can do without being told not to prosecute Gascoigne for drink and drugs as he donates to the police fund. Cowgill is also appalled by Royce's actions, particularly as Royce wants to kill Ann to stop her talking but gives Nevison some hope by suggesting Ann will be released after another ransom payment delivered by Kevin. As a result Helen, who wanted to speak to Catherine, tells her she has changed her mind. Delivering the money to Cowgill Kevin is shocked when Lewis tells him that Royce killed the policewoman whilst Catherine decides to investigate the house where Royce was seen and is suspicious of what she finds in the cellar.

Eighteen months have elapsed. While investigating a bizarre case of sheep-rustling, Catherine discovers the corpse of prostitute Lynne Dewhurst, Royce's mother, whom she had warned to keep away from her grandson. Along with new recruit Ann Gallagher, Catherine joins the investigation. The woman has been killed and sexually assaulted. CID officer John Wadsworth, meanwhile, is more concerned with preventing his mistress, Vicky Fleming, from telling his wife Amanda about their affair, whilst Ann's father Nevison has to sack volatile employee Sean Balmforth, and Clare meets an old flame, Neil Ackroyd. Royce is given consolation in prison by besotted visitor Frances Drummond, to whom he suggests that Catherine killed his mother.

Catherine interviews a prostitute who has survived being attacked by Sean Balmforth, who is subsequently arrested and charged as being the serial killer whilst vulnerable young farmer Daryl Garrs is also taken in for hitting out at the thugs who stole his mother's sheep. Catherine is shocked when, on grandson Ryan's birthday, he receives a lavish present, purportedly from his father Royce, which allows Drummond to suggest to the boy that he is anxious for forgiveness. In fact Royce wants a more direct revenge. As John's wife throws him out Neil tells Clare that he once had an affair with Vicky Fleming and believes her murder to be different from the others.