When Mr. Granite falls ill, A.J. and the gang endure a wacky week with a perpetually cheerful substitute teacher who wears a clown costume, uses hand puppets to talk, and uses magic tricks to saw students in half and make them disappear.
A.J. and his friends get a Personal Digital Assistant named Miss Porter as a substitute teacher, who can order pizza and tell endless jokes, but grows power-hungry when her system is changed and tries to take over Ella Mentary School.