Every four years in the village of Gavaldon, two children are kidnapped by an unknown force into the surrounding Endless Woods, wherein a school allegedly lies where the heroes and villains of tales of folklore are trained.

While most of the children and their families fear the unknown force taking them away, Sophie dreams of attending this school, where she can have her very own Happily Ever After with a charming prince.

Combined with the fact that she lives with her outcast mother right next to a graveyard, she is deemed by the villagers to be a witch and a perfect candidate for the School for Evil.

Following an ordeal in which they both face hours of punishment for disorderly conduct at the end of the day, Sophie agrees to leave with Agatha the first chance she gets.

When the girls figure out the answer to the riddle - True Love's Kiss — Agatha sets out with a plan to help Sophie rise in status enough to get in league with Tedros.

Finally, Tedros promises to kiss Sophie if they emerge as the last two survivors in the Trial by Tale, an event in which the top Evers and Nevers enter the Woods, aiming to survive the night by avoiding teachers' traps and the opposite side.

By having an Ever and a Never come out together alive, they could prove that both sides can be victorious at once in a fight for a happy ending - a big upset to the laws that have always governed the fairy tale world.

Their relationship ends along with the Trial when Sophie refuses to save Tedros from a deadly attack, prompting Agatha's illegal participation to achieve their desired outcome.

In response, Sophie, now a full-fledged witch, proceeds to destroy both schools and attempt to eliminate Agatha in accordance with her fairy tale.

Just as the Storian is about to spear Agatha's heart, Sophie does something that shocks the School Master—she steps in front of her best friend, sacrificing her own life for her.

She and Agatha are teleported back to Gavaldon, leaving Tedros in disappointment as his one true love has disappeared from him just before the Evers’ Snow Ball.

Chainani felt the Disney adaptations took the original fairy tales, which were more dark, complex and filled with horror, and "pasteurized" them to make them more "appropriate" for younger audiences.

With The School for Good and Evil, he wanted to "get back to the core of the original stories and give young readers a taste of what a real fairy tale is.

"[3] Chainani first had the idea of The School for Good and Evil in June 2010 while finishing the development of his first feature film, Love Marriage, as director.

When Chainani was working with producer Jane Startz on an adaptation of The Pushcart War, he presented the idea of The School for Good and Evil which she dubbed books.