Catherine 'Cat' Ballentine is an agent with the CIA.
When we first meet her she is "in the middle of the Atlantic Ocean" (a bit of an exaggeration) having been incapacitated while on a 58' sport fishing boat with the captain knocked out and tied up and the assailant opening the seacocks to scuttle the vessel. Not exactly a happy situation but one which does a good job of describing the kind of situations this very experienced, very capable operative will get involved in.
We learn straight off that Ballentine is a very determined woman not subject to panicking - if you do not panic when you regain consciousness on a sinking boat far out in the ocean, it is safe to say you are foolhardy, which she is not, or made of stern material, which she is.
This operative has been in the service of the Agency for quite some time and has a decent track record to show for it. She is respected in her field and might actually be liked by her immediate supervisor, a hard female taskmaster with the alliterative name of Peanie Purvis.
Ballentine is reluctant to talk about the things that happened to her in her years working in the Middle East just a bit before we meet her. She has been to see the Agency shrink about it but had not truly unburdened herself of the trauma she endured. As a result she still has a case of PTSD. In the short amount she revealed of the horrible situation she witnessed, she is more than entitled to have it.
She is described as being a very good looking woman but she is honest to admit that without make-up, her skin could be "as pale as vellum" with a "perpetually haunted look".
Throughout the two adventures she has an interesting love-hate relationship going with a fellow named Renny. She also has to deal with some very nasty people out for revenge for things that happened during her captivity in Afghanistan.
She also has to deal with her son, Armaghan aka Matthew, a product of that imprisonment, as well as that little boy's half-sister, Mariah, two children she loves very much.