Luke Harrison's dad makes horror movies. It's very fun to be around such scary stuff–especially when you have your own monster museum at home. But when two ventriloquist dummies join the collection, things get real creepy. Real-life creepy! Slappy and Snappy can walk and talk on their own. And they can make you scream on their own. They have a plan to make everyone's lives miserable. Will Luke be able to stop this terrible twin twosome?