Tom Winter is an agent with TEP.
That acronym stands for the Threat "Elimination and Prevention". It was founded in 2002 as "a covert branch of MI5; off the books so the Government could maintain deniability if anything went wrong".
He has only recently joined the organization, coming to it after a four-year stint in the military. He had hoped that the army would help him get himself straight but unfortunately he "returned from Afghanistan every bit as troubled" as when he left for there. His troubles started as he became a teenage and his father disappeared. "Drink, drugs, and petty crime" marked his teen years. Then came a failed transition into adulthood complete with failure as a husband and a father to his young daughter, at least that is how he sees it. It was either the army or nothing for his choices.
His boss at TEP put it straight out: "You've lost your father, wife, daughter, and your mother can't remember your name. Your country is all you have left, you may as well try and save that hadn't you?"
When we first meet him, he is in his late twenties and he is hoping that this latest stage of his life will give him something he has been lacking; If not a purpose, at least something to keep busy enough to not let the demons in his head take over too much. He is determined to not let it be yet another failure but while his intelligence and his earnestness will be very important, he is still very new to the business and yet to learn the hard way that everyone has his or her own agenda.
"Agents with [messed] up backgrounds make the best recruits."