The life of DI Cadi John and the lives of those around her are forever changed by the discovery of the body of a young woman, Mali Pryce, in a river. Mali has been missing since 2011 and the police question where she has been held for all this time. Will the person responsible for Mali?s death strike again? The pressure is on the North Wales police force to find some answers quickly.

DI John and DS Vaughan learn Mali was troubled; nurse Lowri Driscoll escapes from someone who tries to kidnap her on her parent's farm.

Megan Ruddock’s life begins to disintegrate when Ffion her university friend sees the self-harm scars crisscrossed on her arms. Unable to cope, Megan packs a bag and runs away. However, she realises that there is no escape from the turmoil in her mind and in desperation she steps in front of an oncoming vehicle. However, Megan’s nightmare is only just beginning as the vehicle in question belongs to Dylan Harris. Unable to believe his luck, Dylan takes the injured Megan and drives into the night with her.

Megan Ruddock finds herself trapped in a nightmarish world as Dylan Harris brings her back to his compound after she stepped in front of his truck.Megan’s survival instincts mean that she desperately tries to escape but this results in Iona and Dylan dragging her to the basement room in the cellar where she is shackled to the bed and locked in. Nia, Dylan Harris’ little girl, is witness to the atrocities that are performed by her father and grandmother. The compound is revealed to be a place of evil and terror.

Cadi and Vaughan’s investigations lead them to question Bryn Roberts who owns a local reclamation yard. Despite being uncooperative, Bryn tells them of Endaf Elwy, a man who used to work for him and who was imprisoned for the murder of his niece Anna Williams. At the Police HQ, Cadi and Vaughan look at the Anna Williams case files and they are struck by how similar she is in appearance to the other missing and murdered girls. Could it be possible that the wrong man has been in prison for all of these years?

Cadi goes to visit Endaf Elwy at Gladwell Prison. Endaf Elwy has been incarcerated for over ten years, accused of killing his niece Anna Williams. Cadi meets a simple, almost childlike man who tells her of his love of bee keeping. He’s always insisted that he didn’t kill Anna, he just wishes that he had some information that could lead them to the person that did. Cadi’s fear that the wrong man has been serving time for a crime that he didn’t commit is only strengthened by meeting Endaf in person.