Dominika Egorova is an agent with the SVR.
Nathaniel Nash is an agent with the CIA.
Together they make one heckuva team.
Egorova was a gorgeous young Russian woman, beautiful in both body and soul, who dreamed of being a ballerina and had more than enough skill to achieve her goal. Her history professor father and her symphony musician mother did without much so that she could have a chance to do something she loved so much. Her skill and her dedication might on their own have been enough to achieve that but Egorova had extra talents that helped immensely and would play an even bigger part in her life.
First there was her incredible memory. If she saw something or heard something, she remembered it. From the age of five she could name the composer of any piece she had heard and could recite the lines of plays she had watched.
Second, and more interesting, Egorova was at a very young age diagnosed as a synesthete - "someone who perceives sounds, or letters, or numbers as colors". When music played she saw these colors dance about the room. When people talked or thought or reacted to events, she saw colors as an aura around their heads, halos which revealed via hues the true attitude of the individual. Yellow of deceipt. Red of passion. Black of evil. Those were the bad colors she hated to see. Blue was a much nicer color to the young girl. Purple was the best.
Her parents were fearful of what might be thought of their child or worse yet how she might be used with this talent so they strongly impressed upon her the need for totally secrecy about this gift and that was one instruction she took to most seriously. She talked about it to no one ever again.
But she used it. Constantly. And when her father passed away and her own career was destroyed by a horrid act of a competitor in the ballet school and then her disgusting Uncle Vanya saw a chance to use both of these events for further his own career at her expense, she knew what was going on. She might not have an opportunity to do much about it but she knew. And she learned.
This "loving" uncle on her father's side was the rotten soul who forced the young dancer into a totally different line of work and changed her life forever. Familial loyalty was totally unknown to Major General and First Deputy Director Ivan Dimitrevich Egorov, known as Vanya to family of which was few and friends which numbered even less. He, of course, pretended affection but his true nature was pretty obvious to anyone who dared look closely and especially easy for one with Egorova's abilities. When he needed someone close to perform something especially unpleasant and dangerous and even more importantly to keep it a secret, he looked at his beautiful niece and saw a Sparrow.
In the Russian intelligence world, a Sparrow was a woman who used her highly trained and skilled body to create 'honey traps' to ensnare would-be targets into working for the Rodina (Motherland). To these specialists, the product of a unique school, sex in any and all forms was a weapon to be used whenever and however it was necessary to get the job done. No matter what the proclivity or leaning the intended had, a Sparrow knew how to exploit that yearning to get the 'victim' to do as instructed.
Egorova was an unwilling student at that facility. It made her quickly despise the people who would and use such a place. It made her distrust and dislike the government that would employ such people. And that disgust gave her a purpose.
Dealing with her uncle and his cronies and his boss and his ultimate boss, President Vladimir Putin, all made her disgust grow. She still loved her country but not the people who ran it. Keeping her feelings hidden, though, let her operate without their knowledge. That's when they sicced her on Nathaniel Nash.
Nash was the third son of a prominent Richmond lawyer. His grandfather had been a lawyer and had started the prestigious firm that catered so proudly and successfully to all the power players of the South. Daddy had taken his rightful position in the firm and risen to run it eventually. His two older brothers had learned "enough" of the law to take their seats at the table. Nash was supposed to as well.
But he didn't. He studied Russian and thought about public service and listened to the CIA recruitment seriously. He went that route and you'd have thought he had betrayed all that was holy when he told his family he would not be joining their enterprise. He became the black sheep and could not have been happier.
Being an agent was what he was meant to do. He could recruit with the best of them and he was fantastic at guarding his people's safety. Which was how he came to be the contact for one of the best moles the Agency had in Russia. It also became how he proved over and again how dangerous he was to Russian Intelligence and why they needed someone of Egorova's talents to bring him down.
What neither the SVR nor the CIA could imagine is that Egorova and Nash would do something incredibly unprofessional. They fell in love.