A cold case involving the murder of a young woman is reopened decades later when new forensic evidence emerges, forcing the original investigators to confront the past. Karen Pirie, a detective tasked with reviewing unsolved cases, must navigate the bureaucratic resistance and the shifting memories of those involved to uncover the truth. As she digs into the lives of the four students who discovered the body, she faces a web of secrets that have been carefully buried for twenty-five years. The narrative employs a dual-timeline structure, alternating between the initial investigation and the present-day re-examination to reveal how past actions continue to dictate the lives of the survivors.

This novel is widely regarded as a cornerstone of the Scottish crime genre, praised for its intricate plotting and the depth of its character development. Readers often highlight the author's ability to balance the technical aspects of a cold case investigation with the emotional weight of the characters' histories. The dual-timeline approach is frequently noted for its effectiveness in building suspense while providing a comprehensive view of the crime's long-term consequences. The work is recognized for its grounded, realistic portrayal of police work and the persistent nature of unresolved secrets.