1Episódio 1
Single mother and off-duty detective constable Dinah Kowalska pursues a murder suspect through the streets of Manchester, only for him to get killed by a bus. As a result, Vivienne Deering, her outspoken detective inspector superior, instructs her to withdraw her application for sergeant, the promotion going instead to the nervous Joy Freers. On a visit to the morgue, Kowalska sees the corpse of a girl with Down Syndrome, the second victim with that condition to be hauled out of a river in recent weeks, and suspects a serial killer is at large.
2Episódio 2
Kowalska is taken off the murder case as her involvement with Cathy Calvert has made her too subjective but Deering asks her to assist when a student is found dead of an overdose. Drugs expert Randolph Miller directs the team towards a house suspected of being a drugs factory. Former chemical factory employee Angelica Costeros is brought in but refuses to incriminate potential co-defendant Jensen Raphael until Kowalska and Spike Tanner unite to get her to talk.
3Episódio 3
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.
4Episódio 4
The Friday Street team uncover a scam encouraging people in debt to sell their kidneys, while the search for another girl abducted by the serial killer leads to a big breakthrough.
5Episódio 5
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.
6Episódio 6
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.
7Episódio 7
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.
8Episódio 8
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.