After learning about Sherlock Holmes, Humphrey the classroom hamster follows clues to try and discover why Mrs. Brisbane is gone and Mr. E, a fun but not very educational substitute, is taking her place in Room 26 at Longfellow School.

As the Huit octuplets prepare for a St. Patrick's Day parade, Georgia discovers her powers and uncovers the substitute teacher's secret.

Atticus Hobart couldn't feel lower. He's in love with a girl who doesn't know he exists, he is the class bully's personal punching bag, and to top it all off, his dad has just left the family. Into this drama steps Mr. Looney, a 77-year-old substitute English teacher with uncanny insight and a most unconventional approach to teaching. But Atticus soon discovers there's more to Mr. Looney's methods than he'd first thought. And as Atticus begins to...

A.J. and his friends think that Ms. Todd is the strangest substitute teacher in the world, and they decide to investigate her.

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.

Sam, Lucy, and Antonio have a new substitute teacher, who happens to be the great-great-grandson of Orson Eerie, the evil scientist whose spirit possesses and infects their elementary school--and the friends are afraid he may be trying to bring Orson back to life.