Beth Harmon, an orphan by eight years old, is unremarkable. She is plain and she knows it. In the Kentucky orphanage, she hordes the tranquilizers handed to the children daily to quell the ache of dullness and routine.

A formidable math student, she is allowed to clean the blackboard erasers in the basement where she find the janitor playing chess daily. He is a sour old man and pays her no mind until she suggests a move he could have made. She learned the basics of the game by watching and he slowly teaches her the intricacies as she earns the right to learn them. Throughout the process her mind races and her dull, plain existence is replaced by the realization of prodigy.

By the age of sixteen she is competing, under the new freedom of adoption, for the US Open and is on her way to international stardom if she learns to prioritize her chess, her addictions, and the distractions of youth.