Only a week into his job as hall monitor and class protector, Sam Graves and his friends Lucy and Antonio are trying to uncover the secrets of Eerie Elementary, their living and malevolent school--and then Lucy gets eaten by her locker.

For the first time in years Eerie Elementary is planning a science fair, which may not be a good idea in a school which is alive and out to get the students--but when Sam and his friends find a book of experiments that contains all of Orson Eerie's notes, it may turn out to be the key they need to finally understand the mad scientist.

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.

Sam Graves and his friends Lucy and Antonio have used their positions as hall monitors to thwart Orson Eerie's attacks on the students of Eerie Elementary--but now Orson is determined to get them fired before his next attack, planned for the annual Kickball Showdown.

Eerie Elementary is planning a big Halloween-type celebration for Eerie Day, including hosting a "haunted house" at the school itself; but the spirit of the evil scientist Orson Eerie sees this as the chance to finally triumph over the intrepid hall moniters, Sam, Lucy, and Antonio--and it is up to them to prevent a catastrophe and perhaps even defeat Orson and banish him from the school forever.