Goosebumps: How to Kill a Monster

SINOPSE

Gretchen and her brother, Clark, hate staying at their weird grandparents' house. they live right in the middle of a dark, muddy swamp. And things just keep getting spookier as there's something really weird about Grandma and Grandpa's house. Something about that room upstairs. The one that's locked and has those strange noises coming from it...