DI Deering and her team must crack the case of a twisted serial killer - by whatever unconventional means possible.

After Deering and her team lose the serial killer case, the cops see a chance to redeem themselves by investigating a dangerous new street drug. No animals were harmed in the making of this episode.

The serial killer is showing no signs of slowing down, while local racial tensions are also running high when an Asian woman is killed in a suspected racist attack.

The police set up a trap for the prime suspect in the serial killer case, but their plans could be derailed entirely after a notorious child murderer's new identity is leaked on the internet.

Deering leads a manhunt through Manchester as the net closes in on the serial killer. Joy and Spike discover an unsettling slavery case after a brutal attack on a young homeless man.

The fatal shooting of a respected surgeon leads the team to an unlikely suspect. Meanwhile, Dinah and Deering make disturbing new discoveries in the serial killer case, fearing it might not be over.

In the final episode, Dinah clashes with Deering, setting off an irreversible chain of events, and an attempt to save the lives of a mother and baby goes disastrously wrong.