It's Halloween! The Cat in the Hat takes Sally and Nick trick or treating--his way! Around the world they go, meeting three new friends who teach Sally and Nick the tricks that they each do and share the treats that they like to eat. Back home, Nick and Sally are ready to go trick-or-treating, with plenty of new tricks up their sleeves.

Sally is off to fight an imaginary "dragon"! Nick wants to go, too. He doesn't want to stay and watch the baby princess. The Cat explains that babies can be part of the adventure when he suggests that they go meet King Cecil the seahorse, who takes all his babies with him wherever he goes! Nick and Sally discover that taking care of babies is even more fun than fighting dragons.

Nick and Sally set off on a safari with the Cat in the Hat to find all kinds of stripes. Along the way, Sally and Nick discover that stripes serve different purposes for different species. The stripes on Jake the coral snake tell other animals to stay away. Zelda and Zoran's zebra stripes help them to identify each other. And the stripes on an iris attract birds and bees.

Nick wants to learn how to knit a scarf like Sally, but they've run out of wool! A visit to Finola's farm teaches Sally and Nick how wool yarn is made: from sheep to scarf.

Sally and Nick are having a hard time getting customers to come to their "cafe." The Cat takes them to meet Eddy the honeyguide bird. Eddy shows them how he guides humans to bees' nests by making noise and putting on a show. Back at home, Sally and Nick follow Eddy's example and proudly attract their first customer!

Swinging from a rope isn't so easy for Sally and Nick. Good thing the Cat knows Charlie the chimpanzee! In the Leafylafoo Rain Forest, Charlie teaches them how to use their hands and feet to swing as they help him search for bananas.

Sally and Nick are trying to guess which game Harvey the guinea pig might like to play with them. The Cat takes them to meet his friend Katie the cavy, a wild guinea pig. But when they try to ask her, she playfully runs off! With the help of three animals with very different ways of seeing, they finally find Katie and discover a guinea pig's favorite game--hide-and-seek!

Nick and Sally are waiting for Mom to come back so they can play in the pool. The Cat suggests that playing on water is even more fun! A trip to Splishy Splashy Pond to meet Walker the water strider reveals how he's able to stay on top of the water with the help of air bubbles.

Nick and Sally are cleaning up the backyard when they come across a yucky apple core. Who's going to pick it up? The Cat in the Hat takes them to meet the best cleaner-upper there is, Sandy the sand hopper! Sandy teaches them the difference between man-made trash and natural products that might seem like garbage to humans, but are actually food for some animals.

Nick and Sally are about to dump out the water in their kiddie pool when the Cat stops them--water is too precious to waste even a drop! Off they go to the Drippety Dry Desert to meet three creatures that are experts at finding and conserving water.

When Sally and Nick have difficulty sneaking up on Nick's mom to surprise her, the Cat brings them to meet nature's great sneaker-uppers: three big cats. The kids learn patience from a snow leopard, speed from a cheetah, and distraction techniques from a lion.

When Sally and Nick run out of flour for making muffins, the Cat takes them to Finola's farm where they learn how wheat is harvested and ground into flour.

The Cat's friend, Minnie Meerkat, teaches Sally and Nick how they can make their campsite as safe as a meerkat's community.

It's off to Kaloo-Kalee for some leaf collecting! There, Sally and Nick learn that leaves help trees make food, and that's why it's best not to pick the leaves from the branches. They collect fallen leaves from three trees with very different leaves.

A trip to meet three of the Cat's friends (and some styling assistance from the Wig-o-lator) helps Sally and Nick decide what kind of haircut to get next! Should they have yak hair? No, too hot and heavy! Seal fur? Too short. Porcupine? No way! Too spiky!

Nick and Sally run out of ice cubes, the Cat takes them to Freeze-your-knees Snowland to get some. Polly the polar bear introduces them to all the different kinds of ice in her Arctic home.

Sally and Nick are trying to guess what they'll be when they grow up when the Cat drops in for a visit. The Cat is sure Nick and Sally will never guess what his friend Puggle will be when she grows up. Judging from different parts of her body, they start guessing right away! A frog? A duck? A beaver! They discover that, while Puggle may have some similarities to these creatures, she will grow up to be a duck-billed platypus!

Nick and Sally can't seem to find Harvey the guinea pig. The Cat suggests that Sally and Nick might find Harvey by meeting three friends who do things differently. They meet a bird that can't fly, a cat that swims, and a fish that walks on the mud!

For show-and-tell at school, Nick and Sally must bring something from their favorite season. But how can they choose which season is their favorite? The Cat in the Hat takes them to the magical Garden of Seasons where they can visit any season they like, any time they like! They meet three young animals and journey with them as they begin to grow up during the course of two seasons.

It's Nick's turn to choose a favorite season, so everyone goes back to the Garden of Seasons to visit fall and winter! In fall, they meet up with their friends from spring and summer to have a going-away party for Candy the goose who's about to fly south. In winter, they have a great time playing with Sam the hare while all his other friends hibernate.