Strange things are happening at United Middle School, and when the fire alarm goes off without any fire, it's just the beginning. Jake, Emily, Amy, and Max—four curious friends and sharp investigators—team up to crack the mysteries that leave everyone else stumped.

From disappearing lunches to a prank war that spirals out of control, and even a teacher who mysteriously turns into a kid, these young detectives are ready to face whatever oddities come their way. But when they uncover secret rooms, vanishing artwork, and a traveling notebook with clues of its own, they realize some mysteries are bigger than they imagined.

With their wits, teamwork, and a little luck, can they solve all the puzzles hiding in the hallways of United Middle? One thing's for sure—there's no such thing as an ordinary day when the young investigators are on the case!