Nikki and Jack head to Scotland to help earnest rural detective DS Jason Ross investigate the chilling murder of a lap dancer found in a remote forest. In their search to find a suspect, the team clash with rogue city detectives DS Mike MacNeil and DI Simon Laing. But as more human remains are unearthed in the forest, it becomes horrifyingly apparent that a dangerous serial killer is at large. News of the murders unsettles new mother Sarah, who is harbouring a dark secret from her partner Steve.

Nikki, Jack and DS Ross are feeling the pressure to close the net on a serial killer abducting young women. Concerns increase about missing Sarah, and solving her mysterious disappearance becomes an urgent priority for the team.