Jack Kane is a former soldier with the British SAS.
As one of the men in the know sent to find and eliminate him put it, "Kane used to be one of us, multiple tours in the desert. Black ops all over the world. Worked on cross-jurisdictional crews with MI6, Seal, Delta, and CIA Black Ops teams - a dangerous man with too much in his head". That last phrase explains, at least to the powers that be who ordered it, why those men were directed, "If you find him, kill him clean".
Those powers apparently rose as high as 10 Downing Street because Kane had seen something and learned something pretty darned damning and should he elect to talk, "it would bring down the UK Government, and most likely the US Government with it. Too many secrets, too much blood."
When we meet him, though, Kane does not seem like a dangerous man. He is working a blue-collar job and "had worked in the chemical factory for eight months. Before that, he had worked on a motorway maintenance crew for four months. Kane was thirty-eight years old, of average height and build, and found work wherever he could get it. He had to pay his wife maintenance for the children he loved and missed all day, every day. Unfortunately, the skills Kane had spent a lifetime honing were of little use in the real world, so he worked in the factory to pay his way.
His simple and largely mundane job was allowed in the agreement he had made with MI6 before leaving that profession. He had promised to not make waves or trouble. When he finds, when we just meet him, that he cannot simply stand by and watch bad things happen to an innocent woman who didn't deserve it, making trouble is pretty unavoidable for him.
What's more telling is the acceptance Kane has of who he really is: "Kane's true profession was violence, and a deep, dark part of him still enjoyed it. The part men don't want to admit to. He felt the exhilaration of combat. An old feeling, primal, vicious and familiar". So, having saved a woman, he and his family was in danger of losing theirs.
Meeting Kane shortly into the first recorded adventure and soon getting entangled in the mess that Kane had with his former employers is the fascinating and not a little intimidating Detective Inspector in the Serious and Organized Crime Squad based in Manchester, Frank Craven. "He was a head taller than most men, broad-shouldered and heavy with a gut he wished was half the size." He can kowtow just about anyone he faces with the except of his wife. Craven and Kane will soon become friends and will join in a couple of quite action-packed adventures together.