A series of horrific murders of women in a pattern very similar to a previous series of murder Police Detective Jane Tennison investigated lends support to a growing popular feeling that she arrested the wrong man, who has always claimed his innocence. Jane refuses to accept that possibility and orders her team to investigate the new murders to the exclusion of reviewing the older ones. The growing friction of the suspicions of her fellow officers and her own convictions lead to her being taken off the case as being biased. Now, she must try to restore her professional reputation while investigating elements of the case on her own.