Kevin Fulton was one of the British Army's most successful intelligence agents. Having been recruited to infiltrate the Provisional IRA at the height of The Troubles, he rose its ranks to an unprecedented level. Living and working undercover, he had no option other than to take part in heinous criminal activities, including the production of bombs which he knew would later kill. So highly was he valued by IRA leaders that he was promoted to serve in its infamous internal police - ironically, his job was now to root out and kill informers.