Series 18

1. Sniper's Nest (1)

2015-01-06 · 60m

Nikki and Jack strive to track down a sniper at large in London and stem a public crisis.

2. Sniper's Nest (2)

2015-01-07 · 60m

Nikki and Jack investigate links between the victims to close the net on the killer.

3. Falling Angels (1)

2015-01-12 · 60m

Nikki and Jack investigate a man killed by a train on the London underground.

4. Falling Angels (2)

2015-01-13 · 60m

Nikki helps high-flying DI Luke Nelson unearth painful childhood memories.

5. Protection (1)

2015-01-19 · 60m

A suspected paedophile is found murdered in a children's playground.

6. Protection (2)

2015-01-20 · 60m

Nikki, Jack and Thomas focus in on Lizzie's movements on the night of Barge's murder.

7. Squaring the Circle (1)

2015-01-26 · 60m

The nanny of a Russian oligarch is killed in a botched assassination attempt.

8. Squaring the Circle (2)

2015-01-27 · 60m

A young woman working for the Doshis is found dead in Maksim's apartment.

9. One of Our Own (1)

2015-02-02 · 60m

The Lyell team are under pressure to catch the killer of an admired Essex police officer.

10. One of Our Own (2)

2015-02-03 · 60m

When the body of local criminal Jason Simons is found, the course of the case is changed.