In the year since Alexander and his father moved to Stermont, he and his friends in the Super Secret Monster Patrol of Stermont Elementary have defeated all kinds of monsters, but now they face their greatest challenge, the boss-monster who has kidnapped fellow monster fighter Ms. Vanderpants and stolen the Notebook of Doom--and they have to do it before Alexander turns eight and stops being able to see monsters.

When Case arrives at her best friend Drea's isolated West Texas home and finds her missing, she embarks on a search for clues about Drea's disappearance while facing the unsettling, cult-like and possibly murderous behavior of Drea's roommates.