A.J. and his friends are afraid that Ms. Todd, their substitute teacher, has killed their regular teacher and is trying to take over her job.

When Milton Worthy learns his classroom's pet ferret is the evil mastermind behind a dastardly plot for world domination, it's more than just about any kid could handle. But then not every kid is the son of a member of the super-secret, super-awesome Society of Substitutes! Now it's up to Milton and his substitute teacher mom to save Beacher Elementary School before time runs out.

"Keep your friends close and your enemies closer! When Snowball, the puffball hamster in Ms. Kim's classroom, accidentally sips the teacher's leftover protein shake, she transforms into a monster like Beacher Elementary School has never known before. It's all hands on deck to stop Snowball before it's too late. And to do that, Milton Worthy is going to do have to team up with Noah, the part-time classroom ferret, full-time evil mastermind! Will Milton...