Leo does community service on a rough estate after being done for drink-driving.

Frustration within the team builds as Harry and Nikki struggle to find any useful evidence from the post-mortems to help the police. No one will talk, and they have no leads. Leo worries for Levi, who is sucked further into a world of gangs and violence.

The team investigates the murder of a woman found dumped on the side of the road with her face removed.

Harry tangles with a Russian oligarch over the murder of a journalist.

The team investigates an armed raid on a suspected terrorist cell in which two suspects and a police officer are killed.

Nikki faces mounting police hostility to her investigation of the armed raid.

Harry is drawn into the murder of a Hasidic man found on disused wasteland, while Leo investigates the death of an Australian backpacker.

A second Hasidic boy is killed, which convinces Harry they are looking for a Jewish killer.

When one boy is found dead and another is abducted, the team faces a race against time to find the missing child.

As the search for Liam continues, Nikki's loyalty towards her former mentor is tested.

Nikki clashes with Zambian police as she investigates the death of a British medical student.