Karen is a young woman who is refreshingly normal and charmingly out of style. She is not a slick, maverick cop, but her quick mouth and creativity make her a great investigator. When Karen is promoted to the Historic Cases Unit at Police Scotland, she is charged with resuming the investigation into a murder that has been the focus of a controversial true crime podcast. When Rosie Duff, a young bartender, was stabbed to death in1995, the three drunken students who found her body were suspected. But despite police suspicions, the boys were never charged. Detective Sergeant Karen Pirie is still intent on learning the truth about that terrible night, despite the passage of nearly 25 years. Do the men have more information than they've let on? When Karen finds holes in the police's initial investigation, she finds herself at odds with the same policemen who were in charge of the first manhunt.