The three-part serial stars Hayley Atwell as Denise Woods, who tries to solve the murders of three seemingly connected victims across three decades, each of which she believes has been committed by the same offender, Mike Holland (Julian Lewis Jones).
She’s seconded to work with handsome young plain clothes Detective Sergeant Ray Deans.
One September morning, she accompanies him to a crime scene in a narrow lane behind a Brixton nightclub where the battered and strangled body of teenager Amy has been discovered.
Having had a previous encounter with the teenager, Denise is determined to bring Amy’s killer to justice.
As the investigation progresses Denise’s fervour for the case leads her to fall foul of her senior officer, DCI Ferguson.