Livia Lone is a police detective.
More specifically, she is a sex-crimes investigator for the Seattle Police Department and has been for several years, racking up some impressive wins which definitely puts her in the good with her bosses. That is on the official side.
Unofficially and most definitely covertly, she goes on her own assignments, tracking down and eliminating serial rapists who have either totally scammed the system or be able to avoid leaving evidentiary proof behind.
When the rules break against her and a guilty perp walks free, she frets and fumes like her fellow cops and growl at the injustice and then moves on to the next case because that is all she can do. Except, of course, when she puts on her special duds designed to leave no DNA behind and puts on a disguise and heads out into the night to remove the garbage the law couldn't.
And while she works by the law's rules during the daytime and by her own rules at night, she also works diligently to track down what happened to her little sister, Nason, who, like her, was a victim of human trafficking but who, separated from her by the evil ones who sold her away, did not manage to escape and make a new life for herself.
This search will take her to other countries and up against some pretty powerful people in those other lands as well as a few back in her own land. Own being her adopted home in the United States and not Thailand where she had been lived the first 13 years of her life before her parents sold her and her 11 year old sister.
Along the way while she is working on her own most of the time, she will come into contact with, and assume temporary partnerships with, , , and , people who have quite different career paths from each other but who interact now and then. She gets to join the party and she belongs.