DC Lisa Armstrong is asked to assist a murder investigation in Morecambe. The team try to uncover why the victim was targeted, but meanwhile, Lisa and her family are unknowingly stalked by a mysterious figure who has an agenda.

Determined to ignore Andy's unexpected arrival the night before, Lisa throws herself into the case and discovers a significant lead from her only eyewitness. The new information opens up the investigation and the team uncover vital evidence.

Following an unexpected turn in the case, Lisa and the team accept help from a new unit.

Lisa pursues a new line of investigation, uncovering a far-reaching secret.

As a confession brings the team closer to the truth, Lisa identifies a suspect.