Alex King is an agent with MI-6.
And an agent with MI-5.
When we first meet him, he is in his early 40's, a highly thought of and well seasoned operative for the Secret Intelligence Service, at least by some. There are others who think him too old for the kind of field work that he is given and that for someone of his age to still be operational, doing what he is asked to do, there might be something psychologically unstable.
His specialty is taking out targets that need eliminating and he has shown over the years he was capable of doing so from a long distance or from up close. As the man in charge of Special Operations has reason to remark, King is one of his three top agents and the one who has performed "the highest percentage of successful operations". Even though he is starting to get up there in age, he remains "among the fittest" and "passes all the regular mental agility tests". Mind you, that leader is on the pro-King side. Those with opposing viewpoints state "the man must be completely deranged!"
But an action he took in northern Iraq for sound reasons has come to bite him and there are some who, for their own reasons, decide he should be made a scapegoat.
Not to worry, though. As the series progresses, while MI6 might say goodbye, MI5 is more than willing to pick up a highly trained operative and while they might not have quite the need for someone with his deadly abilities quite so often, they certainly can see the use of having his expertise around when needing to stop other assassins from plying their trade against British subjects.
Of course no good deed goes unpunished and as administrations change those in authority change and gratitude is just a word in the dictionary, not an emotion felt in the high offices so King will again find himself where he so often has been: very much needed and very little wanted. Good thing the man has thick skin.
Having a major part in King's life as his story unfolds is Caroline Darby, a fellow MI6 agent when King was working for them. Their meeting was not exactly harmonious and she distaste for King's ability to kill without remorse when needed is well expressed. Over a short time, though their relationship will improve, largely as she discovers just how brutal the opposition can be.
- Alex King "never go used to it ... the impotence of being unarmed and staring down the wrong end of a gun".