All the neighbourhood kids join the Shrinks in their back garden to enjoy Dad's annual Monster Movie Marathon. While watching the scary movies, the kids add to the fun by playing pranks on one another. When something unexplainable happens, Becky and George set a trap. The mysterious prankster is actually a new child who has just moved into the neighbourhood. The children realise their their first impressions were wrong and realise she just wanted to have fun with them and so they make a new friend.