Davina Graham is an agent of the British Secret Intelligence Service.
Despite being female in a male-dominated organization, her position is one of good standing. Having served for five years at the start of the series, she has earned the grudging respect of most of her peers, though respect for one or more of her seniors proves difficult for Graham to keep. Possessing neither great beauty nor physical agility, she nevertheless can enchant when needed and fight if necessary. Usually, however, it is her brain that controls the action for she learns to be a shrewd, intelligent agent. Even when her heart begins to pull her in a dangerous direction, she keeps her focus and doesn't lose sight of who she is and what she is expected to do.
The daughter of a respected retired Naval officer who was a friend of the head of the SIS, she was approaced by that leader to join his agency. At first she was not interested but then she changed her mind though she insisted it be at a low level, allowing her to work her way up slowly and on her own merit. As time goes along, she loves and loses and learns to live again.
As the series progresses, her career takes a huge hit and she all but leaves the field completely. Slowly she and her career recover, eventually picking up steam enough to land her the position of head of the Intelligence agency. Even as she is learning to run the large spy bureau, she still has to deal with family, friends, and the chance to re-find love, not an easy chore when secrecy is the law and deception your biggest weapon.