At the start of 'The Troubles' in 1970's Belfast the British Army needed people on the ground, people they could trust. They searched their ranks to find men willing to live and work within the community and report back. So it seemed simple enough for William Deery, just work on the buses and report back what he saw. He was pushed in at one end and sucked out at the other he finds himself getting deeper and deeper into the murky world of the IRA. All men have their limits and Deery found his.