Stuart has managed to survive his first few weeks at Camp Haunted Hills, a movie camp, so he isn't surprised when Lucius turns into a hairy monster--until he figures out it isn't a trick.
Stuart attends a summer movie camp where a movie producer plans to try out his special effects on the campers, such as a shark rising out of the lake and a witch flying around the campfire.
Stuart looks forward to another adventurous summer at Camp Haunted Hills, but he gets more than he bargained for when he and his friends inadvertently travel back to the time of the dinosaurs.