Boyd has to break in a new team member of equal rank, Detective Superintendent Sarah Cavendish, a high-flyer recently grounded by a hushed-up failed operation.After the empty and abandoned car of banker Donald Rees is discovered threee years after he went missing, Boyd decides to take on the case in an effort help the man's family find some closure with their lives.

Boyd is convinced that the missing Donald is not a murderer, and pushes his team to try to make sense of all the vague connections in the case and eventually confront the unfathomable evil lurking within the heart of this sad, unfortunate family.

After a woman is discovered stabbed in the eyes and incinerated in her car she is identified as Claire Somers, a neglected child who was taken into care, then later kidnapped in 1986 at the age of seven. Robert Fenchurch had his eyes stabbed out on the night Claire was kidnapped as her abductor fled the scene. The team soon find out that Claire had snatched 15-year-old Abigail Harding, who was found locked in a hotel room.

The investigation into Claire Somers' death has seemingly unleashed a predator straight from the darkest childhood nightmare. But are they looking for a monstrous child-stealer, or misguided saviours?

When the squad look in to the case of an army activist discovered in London's sewer system they discover that the case may have more police connections than they originaly thought.

As the case continues, the squad investigate Murray using Grace as bait. However, when one member is shot and one member is arrested, the case could go in to turmoil, only for a connection to be revealed.

Boyd suspects a cover-up when a missing student's DNA matches with an unidentified corpse.

Boyd needs Sarah's expertise to help expose the state's involvement in Barclay's death.

Boyd investigates the disappearance of 16 homeless boys from Waterloo Bridge in the 1980s.

Time is running out for Boyd as he fights for justice against a powerful adversary.