In the final investigation I of the series about state responses to terrorism Peter Taylor uncovers the story of how Army Intelligence and MI5 recruit and deploy agents within Northern Ireland's paramilitary groups. The report focuses on two agents. One was for many years one of MI5's top operators in the Province, feeding information to the security services that succeeded in saving lives. In a first interview with an MI5 agent, the film reveals the process of his recruitment and how he operated. He claims to have taken on the work not for money but for moral reasons, to help prevent terrorist killings. He is still alive, whereas IRA man Gregory Burns is dead. His naked and hooded body, along with those of two other alleged British agents, was found last year dumped in South Armagh. All three had been "executed" by the IRA. The programme has gained unique access to the records of their final "confessions" in a film that defines the secret battleground between the British state and terrorists, Loyalist and Republican, in Northern Ireland.