Thea is a computer programmer in the private sector. Max is an agent with the CIA.
Thea Spencer works for an application development firm high enough to be a project lead but still able to get into the programming innards which is good because it is not only what she is extremely good at, it is what she adores doing. She has been with the company for several years and has no interest in trying anything else but when the challenges and the thrills of what Max offers comes along, she is eager to jump onboard.
Max is the agent. He is, from all descriptions and attitudes, a major gift to women and while he does not believe it absolutely, he is in agreement enough to be surprised when his dashing, never-fail charm gets a surprising bump in the nose when it is dangled in front of Thea.
Max is not Max's name. When he first introduces himself to Thea it is with the alias of Dominic Walker (at least we think it is an alias). When Thea learns that instead of being a lawyer as he first presented himself, he is in fact with the government, she teasingly names him Max in memory of Agent 86 of Get Smart fame. Another fun dent in his self-image.
Together they have adventures which should have been simple and relatively safe but then the bad guys decide guns and knives are appropriate and safe flies out the window and simple fades away. When things get nasty, Max learns quickly that though she is not a trained agent, Thea is no damsel in need of saving and Thea discovers that Max really is a good at taking care of himself as he pretends.
Oh, then there is "D." who is Max's partner who stays in the background but keeps helping out.