When a London hospital is evacuated it leads to the discovery of a tragic death. DS Ronnie Brooks and DS Matt Devlin are assigned to the case and it leads them to the Kings Cross area of London.

A 13-year-old boy is found kicked to death at Euston rail station. DS Ronnie Brooks and DS Matt Devlin discover that the boy's mother boyfriend is suspect.

When an ex-vice officer is found dead, DSs Brooks and Devlin uncover unsettling truths about the victim's private life. In court, Crown Prosecutors James Steel and Alesha Phillips face an old sparring partner of their boss, whose client claims to have acted in self-defence.

The discovery of a body in a shallow grave prompts DSs Brooks and Devlin to reopen an eight-year-old murder case. The man convicted of that murder is given leave to appeal and chooses to represent himself in court.

The remains of an eight-year-old boy are uncovered, twenty-five years after he was reported missing. DS Brooks and Devlin re-interview the man arrested during the original enquiry. The boy's childhood friend reluctantly agrees to undergo EMDR therapy and appears to recall the events of the night that Tommy disappeared.

DS Brooks and Devlin investigate an arson attack on a Turkish social club, which left seventeen dead. A complex investigation leads to the arsonist, but there is doubt as to whether he was working alone.