As part of Radio 4's Secret Britain series, Peter Taylor meets people who keep or have kept the darkest state secrets, to hear how it feels to live a life in the shadows:

The Derry family who put their lives on the line for peace; the Muslim agent who spies on Islamist extremists; the mandarin charged with guarding Britain's secrets; and the Special Branch officer who infiltrated subversive revolutionary groups.

Presenter: Peter Taylor
Producer: Richard Knight. Show less