Alexander and his new friend, Rip, are worried that the worms the rain has brought out are really the megaworms that Notebook of Doom describes but they soon discover that the night crawlers are trying to warn them about the monster tunnel fish that are threatening Stermont Elementary.

Alexander has just moved into Stermont, but the elementary school is being torn down, his new classroom is located in the hospital morgue, a notebook he finds is full of information about monsters--and everywhere he turns there are spooky balloon men determined to attack him.

When Clyde gets excited, he turns into a monkey. His twin sister, Claudia, is always trying to calm him down, especially at school. The principal does not like a monkey loose in the building. But when Clyde and Claudia get a surprise new neighbor, Clyde will come closer than ever to being caught.

Fergus and Zeke are the class pets in Miss Maxwell's room, and they do everything the students do. So when it comes to the science fair, they want to do an experiment, not be an experiment.

"When her teacher assigns a new team project for Earth Day, Ellie can't wait to pair up with her best friend, Hannah. After all, as a superhero, it's Ellie's job to save stuff--including the planet! But the project soon becomes more than Ellie's super-skills can handle. She decides to use one of her parents' super inventions to create a copy of herself. But when Ellie #2 threatens to take over, it's up to the real Ellie to bring the project back down...

A heavy snowstorm traps the students inside Eerie Elementary, a living, breathing monster brought to life by mad scientist, Orson Eerie--soon the school begins to freeze from the inside out, and Sam, Lucy and Antonio must find a way to get the heat back on before all the students freeze to death, while facing the truth that Orson Eerie is even more powerful and dangerous than they realized.

Missy wants to take home the class pets, but another girl, Tiffany, has already asked their teacher so Missy and her friend Oscar need to come up with a plan to make Tiffany change her mind.

The Notebook of Doom is missing and Alexander and his fellow monster-hunters Rip and Nikki are convinced that the boss-monster has it. But is that monster the mysterious Principal Vanderpants--who is certainly behaving oddly--or someone else? They need to figure that out quickly because a mistake could have deadly consequences for Stermont Elementary.