Maggie Black is an agent with The Unit.
To anyone who bothered, or was able, to follow her as she headed to its headquarters, when she was in town she showed up at the five-story office building of Inked International, a global stationary supplier. That is what the civilian world saw. Those few in the know, however, it is by the name of The Unit. "Strictly speaking, the Unit didn't exist. Unlike the Secret Intelligence Service at Vauxhall Cross or MI5, everything about the Unit was underground. Only those with the highest clearance were privy to their inner workings. Unlike their public counterparts, the Unit's activities weren't strictly legal. When the need arose to step outside the law for the greater good, Maggie and her colleagues shouldered the burden and did what others could not."
While he is not the Director of the Unit, Bishop is the man that Black, and all the other operatives, report to, the man that knows everything anyone is doing and it sometimes sees what they are thinking.
Black has been an agent with the Unit since she joined at the young age of 16, just out of school and looking for a challenge. That was over a decade before the time we first meet her. Now at 27 years old, Black is considered by many to be the best agent that the organization has. This means to some that she gets the choicest assignments, being Bishop's 'pet' but to others, it means that the most dangerous and problematic missions get passed to her. Reading the stories of her cases, the latter seems more likely.
Life will change as the series goes on and Black will be forced to change with it but with each problem comes a chance for improvement and Black is, if nothing else, one persistent survivor.