A cold murder case from 1990 brings detective superintendent Elizabeth Bancroft and detective sergeant Katherine Stevens together.

Katherine and Anya struggle to find any forensic evidence concerning the Fraser case. Meanwhile, Katherine and Joe's relationship moves forward.

A shocking blast from the past brings the spotlight back on events from 1990; Katherine faces a chilling truth.

Katherine and Anya are determined to uncover the truth of the Laura Fraser case once and for all; Bancroft has no options left other than to reveal her secrets.

Promoted to Detective Chief Superintendent, Bancroft enjoys professional success but at great personal cost. When a double murder brings an unexpected reunion, Elizabeth is forced onto the sidelines.

With the evidence around the Connors' murders building, Harper and the team are met with conflicting accounts. Elizabeth is forced to choose between her professional and personal loyalties.