It follows the magical adventures of 6-year-olds Nick and Sally, who travel the world with the Cat in the Hat as their guide. As they travel in the Cat's customized vehicle, the Thinga-ma-jigger, which can float, fly, drive and even ski, they learn about natural science, visiting the rainforest, the bottom of the sea, and all places in between. They're joined in their travels by the Cat's mop-headed sidekicks, Thing One and Thing Two.