Quick recap
Sonny and Sam, who run a junk-hauling side gig, find an unpublished Goosebumps manuscript in R. L. Stine's old house. Opening it wakes Slappy, and Sonny's sister Sarah gets pulled in. On Halloween night, Slappy uses a mask to take over Walter, the local store manager, powers up the Wardenclyffe Tower and brings the town's decorations to life. Then he kidnaps Kathy, Sonny and Sarah's mom. The trio breaks into the tower, and Sarah combines the manuscript's power with the reactor's energy to beat the dummy. Kathy and Walter return to normal, and Stine shows up to praise the kids. In the final scene, a surviving Slappy traps Stine himself in a new story.
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