A.J. and his friends launch their own investigation when they get stuck with weird substitute Ms. Todd, and begin to suspect she has kidnapped their regular teacher in order to take over the job.
Mr. Docker, a new science teacher, is a crazy inventor who blows things up, uses potatoes for power, and has A.J. and his friends wondering whether science is for nerds or is the coolest subject ever.
The new lunch lady at Ella Mentry School, Ms. LaGrange, writes secret messages in the mashed potatoes and is trying to get the students to eat healthier foods.
Boring Mr. Loring retires, and A.J.'s class gets a new music teacher who raps, break-dances, and thinks he has what it takes to become a famous musician.
A.J. and his classmates are convinced that new school librarian, Mrs. Roopy, has multiple personality disorder because she keeps pretending to be famous people.