Jayne Bond is an agent with the VIS.
That acronym stands for, prepare yourself, the Vampire Intelligence Service. "Preternatural protector of humans. Champions of the underdog. Our secret operations, equivalent to the British government's Secret Intelligence Service, had been saving the world for centuries from evil villains they had no idea existed." That is how Bond describes it and she should know. She have been an agent with them for one hundred years. The organization is currently run by Truly Solani, aka 'T'. Bond understands why, with a first name like Truly, her boss goes by an initial, as she states, "Sounded more like a greeting card than the given name of a high-powered Director of Covert Operations."
Bond is, as stated, one of the department's best agents but she is frequently in hot water with her bosses, as she is when we first meet her, because unlike all the other top operatives, she refuses to totally give up her soul. "We were meant to shed our humanity like snakeskin, and that shift was supposed to happen within one hundred years of being turned." So far she has determinedly held on to at least a piece of caring, no matter what the cost is. Even if this means have to "go rogue to save random humans".
Bond has been a vampire for just at 100 years. She was (likely) in her mid-20s when she was turned, as the process is called. According to her, she had been on a walk in Hyde Park in London 'right after World War I' with a co-worker at Naval Intelligence (showing she had a connection with Intelligence gathering as a human) when they were attacked by a pair of vampires attached to the German Imperial Army. The friend was killed. She was turned in the hope that they could make her a double agent. It did not work out that way and once she had learned "everything [she] needed to know about being a vampire", she ended their existences.
She stated that once she had removed her attackers, she joined something she called the Office of Strategic Service (not the precursor of the CIA) which later "evolved to the VIS". Since that time she has grown to be a very capable, dependable operative, albeit one that can almost be counted on to go her own way if she feels it warranted.
Bond has an interesting relationship with Lucian diAvolo, a being she refers to as her "demon-with-benefits" and considering the description she gives of him and his impressive physique, those benefits took place as often as both can schedule it. He, by the way, is also an agent, working as he does and has for some time for the Demon Intelligence Agency.