The Armagh Signal. Special Branch - The Irish Files, #6

Captain Defoe local commander in Armagh in the North travels incognito to a quiet law office in Waterford - he asks to speak to Mr. Coil as a matter of urgency. Coil / C. I. O'Donnell of Special Branch - shows him into his small office. Defoe explains he is stationed currently at the old Drumadd Barracks in Armagh and is responsible for planning and action raids on suspected para-military objectives.
He was also responsible for a secret listening station within the barracks for GCHQ. This is why he sought out help from Special Branch - he had contacted his superior in the ministry of Defence who in turn told him to come see a certain solicitor in Waterford. This confused him, but he followed orders and here he is! Paddy Coil leaves the room to check on Defoe and see if he is who he says he is.
Reception in minutes comes back with a background check - Defoe is being short-listed for a future in MI5 (although he is not aware of this), currently he is a Captain in the Coldstream Guards (Second to None) and is being given responsibilities to check his trustworthiness in confidential work. C. I. O'Donnell returns and shows Defoe his real credentials, but tells him nothing of the background check.