Stewart has plenty of reasons to dislike his new art teacher, Wanda Gibbs. Not only did she give him the awful nickname “Wart” at school but she has also started dating his dad. She must have placed his dad under some sort of spell, which is entirely possible since, according to her very own son, she also happens to be a witch. 
But nobody, including Stewart’s father, will believe this outlandish accusation, even though Wanda suggests that if Stewart will support her, she might use her magic to his benefit. Stewart can’t help but notice his athletic ability mysteriously improves every time Wanda shows up at his basketball games. Is it really magic, or is it just Stewart’s imagination? It’s going to take a lot of ingenuity to solve the mystery of Wanda Gibbs.