Callista Jones is incredibly unattractive. She describes herself in baby pictures as more Gargoyle than Gerber's. By the time she's five, she disappears from family photos. In grade school she is labeled "fugly." In middle school she is bullied. Being a math genius does not save her from being the ongoing target of ridicule and derision. In fact, in high school the taunts and mistreatment escalate as peers jockey to find their place in the social hierarchy.
When she finishes her PhD in record time, she lands a job with a large company and anticipates that her intellect and willingness to work hard will make up for her unappealing face. Unfortunately, instead of getting credit for her first big success, her handsome boss publicly credits an attractive young woman who had been the gofer and management liaison with being responsible for the project's achievements.
At this point, all of the wrongs and put downs Callista has experienced over the years come crashing down on her like a tidal wave cascading onshore, washing away moral hesitation and fear of consequences. She seeks retributive justice, not just on her boss and project colleague, but on everyone who has robbed her of happiness in the past. From spamming to murder, whatever punishment she decides is appropriate for the offense.
When her moral compass is reset by an unexpected friendship, a new job and some cosmetic surgery, she begins helping others who have been victimized. Then she becomes the target of an unjust accusation, and everything she has sacrificed so much for starts to slip away.