The primary protagonist of the novel is Charlie, a 12-year-old genius with an IQ nearly equal to Albert Einstein’s. She speaks 12 languages and studies mathematics and theoretical physics in college. She also has athletic skills in skateboarding, snowboarding, and skiing. She is described as a multiracial individual whose appearance allows her to blend in with most ethnicities. She is also rebellious and sarcastic, with little trust or respect for authority. CIA agent Dante Garcia is her half brother.

In addition to her intellectual genius, she is also socially adept and good at understanding people and their motives, a fact she uses to her advantage to thwart her parents’ attempts to profit from her abilities. When her parents try to make her famous, using means such as television appearances, she hides her true brilliance and pretends to be average. Then, she escapes her parents as soon as she can by attending college at the University of Colorado (where she often skips class in favor of skiing in the nearby mountains).

At eight years old, Charlie develops a security program, which she naively sends to a tech company, requesting a fair price. The company steals the program. In retaliation, Charlie hacks into their systems and steals $40 million, which she believes is rightfully hers.