Max and Arthur are best friends who both want to make art. Max is a beginner. Max's first attempt at using a paintbrush sends the two friends on a whirlwind adventure with paints, pastels and pencils, which turn out to have unexpected pitfalls.
When Louis gets eaten up by a Gulper, his big sister Sarah knows she has to act fast, and sets off in hot pursuit. But rescuing a boy from a Gulper's tummy isn't so simple - especially when other strange and scary creatures are looking for their dinner too. . .