Nadine Marshall

Happy Valley star to lead new compelling cop thriller for ITV

Creator Kris Mrksa has based the series on the first-hand experiences of a witness protection officer who served in the Met for 30 years; a job that is "darker, murkier and far more complex" than most of us realise, teases the synopsis.

Many protected people are themselves criminals, which means officers often have to morally compromise, and they have to actively distrust their own colleagues to maintain maximum secrecy.