Lexi Carmichael is a cyber-security expert.
From a young age Carmichael was fascinated by numbers and was very good at using them. Arithmetic moved into Math which begat Algebra, Trig, Calculus, and so on, all were fun and easy to her. Then she got her hands on a computer and they "were my only friends and the Internet, my playground". She became at home in that virtual environment and enjoyed it.
Just turning 25 as the series begins, she is an "information security technologist" with the NSA, web surfing while on the look-out for bad guys. Her main job was to "stop hackers from compromising America's national security". As the series progresses, her career will change at times but her expertise in cyber-security will always be at the forefront of whatever she tackles.
Carmichael describes herself in a very straight-forward manner as being largely on the plain side, especially when next to her mother Clarissa, a former first-runner-up for Miss America as well as once being Miss Teen USA. Now in her mid-50s she still commands the room. Carmichael does not and never likely will. She is not bothered by it but does chafe at her mother's persistence at getting her married to some up-and-comer.
Joining Carmichael on her numerous adventures and missions and escapades are a few close friends. First is Basia Kowalski, a very attractive college roommate of Carmichael who has remained a best friend since those days at Georgetown. Basia is a language expert and picks up new ones almost like a hobby. As Carmichael changes employment, Basia rides with her.
Also an intricate part of the cadre are the Zimmerman twins, Xavier and Elvis. "Everyone at the NSA knew the Zimmerman twins. They were extremely odd people, identical twins marching to the beat of a completely different drummer. They were also incredible math and physics geniuses and had been the stars of the InfoSec department until they were lured away by a huge computer security firm in Baltimore for boatloads of money." Next to Basia, the Zimmermans are her closest allies.
Carmichael's recorded time with the NSA is not long. A new career path is offered when a man she meets, sort of fights with, and leaves handcuffed offers a job (how's that for an interview). A new private company specializing in cyber-security is perfect for the young woman and the fact that her new boss is handsome does not hurt.
Nor does the fact that a mysterious beef-cake of a man who is also a hacker extraordinaire keeps popping into her life. He goes by the name of Slash and Carmichael is truly smitten.
Amongst all these friends and colleagues and would-be amours, there are also a lot of interesting assignments that has Carmichael constantly trying to stay alive.