In her sixth outing as lead detective of Scotland's Historical Cases Unit, Detective Chief Inspector Karen Pirie is struggling with the loss of her murdered partner, Phil Parhatka. Although she has grudgingly begun a new relationship, she cannot escape the rage she still feels for Phil's assailant. Chronic sleeplessness continues to plague her nights, walking the only panacea for these dark hours.
Heading the highly specialized unit is the perfect niche for Pirie, backed up by the consistently reliable Detective Constable Jason Murray, affectionately known as "the Mint." With two odd cases sitting on her desk, Karen is happy to throw her energy into breaking down the complexities of each death and the perpetrators responsible.
The first case concerns a battered body found in the waters of Scotland's First of Forth, no identity available for the unfortunate gentleman. The second case is specifically assigned to Pirie by Assistant Chief Constable Ann Markie, a hard taskmaster whose dissatisfaction is avoided at all costs. This unexpected assignment also includes the assistance of Detective Constable Daisy Mortimer, on loan from a Fife-based crime unit.
Trusting Jason to gather relevant details on the first victim, identified as James Auld, Daisy and Karen begin the more intricate work of researching historical facts on a case that requires forensics to ascertain the victim's gender as well as the victim's identity. Having been covered by a tarp in a garage for a long period, the body has begun to decay. To further complicate the investigation, the owner of the home where the body is found has recently died in an accident.
Pirie and Mortimer travel from Paris to Dublin and back to Scotland in search of interviews with people who have known the victim, assembling a picture of the murdered man's life, links that eventually will lead to his murderer. Each case has its particular complications: the body in the camper is especially fraught with mystery, an assortment of distractions, secret identities, an enlistment in the Foreign Legion, random infidelities, even a crash course in the elite world of fine art and wealthy collectors.
McDermid is the master of police procedurals, all set with a unique Scottish flavor against stunning landscapes, a plethora of quirky personalities, details from the past linking to the present. These two cases and the people involved in the life-and-death dramas, allow Pirie some relief from her private grief, determined to find answers for the loved ones of the dead. Jason and Daisy do their best to contribute to the arrests, Daisy's temporary assignment extended as COVID-19 intrudes into the world of criminal investigation.
As is her style, the prolific McDermid delves into the dark recesses of the human psyche, criminals at their worst competing with personal decisions. Intimately familiar with death, she flushes out the secrets of both victims and suspects, a network of specialists providing critical scientific details to close a case. Pirie is an astute student of humanity, adapting to life's lessons in the face of death, her current grief perhaps the most poignant: "Nothing consoles you for the loss of someone you love... you move forward, but you move in a different way."