DCI Ross Tanner (Clive Owen) makes a startling discovery as he begins work on a high profile case in the Specialist Elite Murder Unit with DI Catherine Tully (Claire Skinner).

DCI Ross Tanner can't escape the truth about his diminishing eyesight while investigating the brutal murder of a 19-year-old, found dead in a tree house. Desperate to protect his secret and career, he reluctantly allies with DI Catherine Tully. Part 2

A police detective, who hides the fact that he's going blind, investigates a woman with a sleep disorder who wakes up covered in the blood of her fiance.

Tanner and Tully have a surprising breakthrough about Matthew's stepfather, Adam, but will it help them solve the case?

The unsolved murder of pop violinist Vicky Ingham is the first case for the elite new Special Murder Unit headed by DCI Ross Tanner (Clive Owen). With Tanner struggling to conceal his failing eyesight from the team, DI Catherine Tully (Claire Skinner) riskily oversteps her authority leaving him professionally and emotionally exposed.

Tanner is convinced that the key to solving the vicious murder of Vicky Ingham is her young son. Tanner's extraordinary plan creates conflicts within his handpicked team that threatens to overwhelm him.