Meet Miss Cast, the most powerful and evil witch in history...who has retired from witchcraft to become a schoolteacher!

“You might have suspected your teacher is a witch, but has she ever actually turned your class into a room full of frogs? Mine did."

Miss Cast is the new teacher, and at first, she doesn’t seem much weirder than any other teacher. But when Gareth sees the pointy hat, cauldron, and a bat living in her hair after being hit by a mysterious purple firebolt, he can’t deny there’s something really different about Miss Cast.

Oops! The world's most powerful witch let her wand slip and accidentally cast a spell so Gareth can see through her disguise!

He realizes that with a secret witch on his side, he can finally get revenge on both the enemy who cheated in last term’s egg-and-spoon race and the headmaster who stood back and let it happen. When Miss Cast loses her temper and changes the headmaster into a hamster, he is sure he made the right choice.

But when she then transforms the whole class and every single other kid on the planet into frogs, Gareth realizes he might have let his thirst for revenge go a tad too far.

“Because, there’s a special rule for transforming children I might not have mentioned. It’s not like with adults, who can go back and forth.”

“What are you talking about?” I said uneasily.

She turned to me.

"Unless we find that wand and change them all back before sunset, they stay this way forever."

Is Bishop Bumford doomed to be ruled by a hamster forevermore? Can they reverse the spell before sunset? And will Gareth ever find it in his heart to forgive the heinous crime committed against him in the egg-and-spoon race?