This is one of a series which takes an experiment-based approach to science and is designed to fit directly with the National Curriculum at Key Stage 2. The books feature episodes in the life of an eccentric family with a fascination with science experiments, which are woven into the storyline for children to try at home. In this story about forces and motion the dastardly Motion Man is on the loose in Duckpool, and Susie Spark is whisked off to stay with Grandpa Grimlight to keep her out of harm's way. But she gets more than she bargains for when she decides to explore the spooky disused fairground behind Grandpa's house.