When Leo's friend commits suicide, Harry and Nikki are called to the scene of a violent and calculated murder, which is thought to be the work of an apparently dormant serial killer.

Harry and DI James deviate from the original investigation to secretly test DNA evidence from the rival Chesham laboratory to try to solve this stalled case.

Harry is disturbed to be called to a crime scene at the home of a family he knows, and finds the bodies of the mother and her teenage daughter, while her stepson lies in a coma - although her toddler has been left unharmed. The police suspect the woman's husband to be the killer - but the pathologist is not so sure of his guilt. The double-murder investigation reveals more about the tangled lives of the inhabitants of Magnolia Drive

Harry and Nikki delve deeper into the tangled lives of the inhabitants of Magnolia Drive.

Serial killer Arnold Mears Eenjoys poetry but has no remorse for violently killing three teenagers. He has been busy for the last five years sending Annie, a desperate mother of a missing girl, on secret hunts to try and find his hidden victims.Annie’s son Andy, upset at Mears’ manipulation of his mother, ends up turning to Nikki for help. Leo manages to get himself into tropuble with the team after he re-examines a case by Nikki’s old mentor, Dr. Helen Karamides.

Nikki manages to track down the original detective on the case, Detective Inspector Gladwyn ans she looks around the church that killer Arnold Mears used to attend as a boy. Mears is not happy that the police have been made aware of the undiscovered bodies and he says that he is prepared to reveal where he has hidden them to Nikki.

Prison officer Daniel Kessler and Ellis Roberts refuse to reveal anything after child-killer James Wade suddenly dies in his cell. Harry meets Wade’s sister Miriam and agrees to help find her brother’s killer

One of Delaney’s patients, Eve Gilston, is discovered dead in her bed. The coroner’s verdict is sudden arrhythmic death syndrome but Delaney is not convinced and gets Leo to investigate. Suspicion soon falls on Eve’s dad Anthony, who lost the family fortune, and his wife Beth.

Leo is determined to learn the circumstances about the death of Eve Gilston. Nikki and Harry manage to find the nun who performed the exorcism but are surprised by what they find. Eve’s mother Beth Gilston is confronted by Leo and che omes close tod iscovering the truth about what actually happened the night before her daughter died.

Nikki stumbles across a sinister underworld where teenage girls are groomed for sex and forced into prostitution.

Harry and Nikki make a crucial connection between the dead girls and sex-grooming victim Shannon, but is it too late for Hannah and Lauren?