When Orla Payne was seven years old, her brother Callum mysteriously vanished. Shrouded in complicated family matters, namely their parents' divorce and the suicide of their uncle, there were no clear leads about his disappearance. The case was eventually dismissed, as the police concluded their uncle killed himself out of guilt over murdering Callum, despite the fact that the boy's body was never found.Twenty years later, Orla is still haunted by the tragedy and remains convinced of her uncle's innocence. Through working at the residential library, a position she took in order to be near the Hanging Wood where the terrible events took place, Orla gets to know historian Daniel Kind. It is he who recommends she contact DCI Hannah Scarlett, head of the local Cold Case Review Team, to see if she'll be able to help in finding out the truth.But Orla's drunken, incoherent phone call leaves Hannah confused and she's left doubting if there is anything to be done on such a long-dead case. But when Orla is found dead, she reconsiders, partly out of sense of duty and partly out of guilt, and discovers that investigating the past can throw up some very dangerous truths indeed.