February, 1979, 'The Winter of Discontent'. Economic chaos has led to widespread strikes across Britain.
Jane Tennison, now a Detective Sergeant, has been posted to Peckham CID, one of London's toughest areas. As the rubbish on the streets begins to pile up, so does the murder count: two bodies in as many days.
There are no suspects and the manner of death is different in each case. The only link between the two victims is the location of the bodies, found within a short distance of each other near Rye Lane in Peckham. Three days later another murder occurs in the same area. Press headlines scream that a serial killer is loose on 'Murder Mile' and that police incompetence is hampering the investigation.
Jane is under immense pressure to catch the killer before they strike again. Working long hours with little sleep, what she uncovers leaves her doubting her own mind.