Ian Stone is an agent with the Board.
Exactly what the Board is we never learn. In fact, I can not be absolutely certain that the organization for which Stone works, and has worked for quite a few years already, is called the Board. I just know that the irascible, often cantankerous man, Commander Thomas Brady, running the department is known as the Chairman of the Board, or as we see it displayed, the "C of B". For that reason, I have dubbed the group the "Board".
Stone is a dashingly handsome man nearing 50 years of age, possessing lush black hair graying at the sides, incredible blue eyes, and an infectious grin that could charm the socks off anyone (not to mention what he can get the ladies he woos to discard). He has been there and done that and probably has scads of tee-shirts to prove it, not that someone as sophisticated as Stone would ever been seen in public in such attire.
One problem that Stone has which plagues C of B, though, is that he has a tendency to spend money. Lots of money. Taxpayers' money. More importantly, the Board's budget money. C of B would love to put Stone out to pasture if only to stop the hemorrhaging that he feels happens whenever Stone heads out on assignment. Stone has one foot and a couple of other toes out the door and does not really know it.
He has not been totally jettisoned, however, because of Ben Smythe, a key accountant for the organization, who frankly worships Ian Stone and all he has accomplished. Smythe wheedles and nags C of B to hold off firing Stone. The compromise that C of B offers is that Stone can stay on but only if Smythe sticks to him like glue and makes sure that the spending is kept reasonable. For that reason, in the few recorded adventures we have of Stone, ace covert operative, we have at his constant side Smythe, ace bean counter and devotee.