Madeline McCallister is an agent with the CIA.
Specifically she is an operative working with the highly specialized Special Activities Division who carries with it the connotation of visiting exotic locales while dealing with extraordinary opponents. When we meet her in the first recorded adventure, she is sipping very watered-down warm beer in a disgusting dive in Juarez which was so dirty "cockroaches would hesitate to touch the floor". To say the least, she is not thrilled.
Still, McCallister is one of the Special Operations Group (SOG) subsection of SAD and she considers herself as as "SOG through and through" so what it takes to get the mission done, she is game for.
McCallister came "from a family that was always big on being proper. My parents were New England blue blood through and through. Cape Cod in the summer type of folks. They raised me to have manners and be respectful like a lady should. Then they died in a boating accident like the worst kind of east coast cliche and in my adolescence discovered a lot of things about myself while rebelling to manage my grief."
She was 16 when they died and she went through a couple of years of acting out her anger. "It took me a while to realize that I didn't hate the person my parents raised me to be and learned to embrace that part of myself. Of course by then I had already been through basic training and was a few years into my career with the Navy. The person that came out the other side was a strange amalgamation of two worlds that was distinctive enough to catch the attention of certain people within the Company."
When we catch up with her, she is two years of constant missions with SOG/SAD and shows no signs of slowing down.