When the Police Service of Northern Ireland are unable to close a case after 28 days, Detective Superintendent Stella Gibson of the Metropolitan Police Service is called in to review the case. Under her new leadership, the local detectives must track down and stop a serial killer who is terrorising the city of Belfast.
The story of former Ulster Volunteer Force member Alistair Little. Twenty-five years after Little killed Joe Griffin's brother, the media arrange an auspicious meeting between the two.
There is something horribly wrong with the bodies found in the dark city streets. Some are mutilated while others have the Price equation (wΔz = Cov (w,z) = βwzVz) carved into their flesh. Detective Eddie Argo and his new partner Helen Westcott unearth the meaning of the odd equation and realise each victim is being offered a gruesome choice: kill your loved ones, or be killed. Before long it becomes clear that the perpetrator has suffered a similar fate and is now coping by seeking a way to solve this philosophical dilemma.
