Just before Halloween, Sonny Quinn (Jeremy Ray Taylor) and Sam Carter (Caleel Harris) discover a decrepit house and decide to explore inside. A hole in one of the walls opens up and inside they find a box that holds a single book: "Haunted Halloween" by R.L. Stine.

When the two friends unlock the book, a ventriloquist puppet begins to talk to them, but that's just the beginning of the utter mayhem they've unleashed in the form of all kinds of strange and frightening creatures that run amok through the town.