As Ms. Frizzle leads the way, the class takes an exciting exploration through the Ralphie Robot to learn about bones, joints and muscles, a journey through Arnold's digestive system, and a pulsating excursion through Ralphie's bloodstream.

The class needs a new mascot for its soccer team. Phoebe suggests butterflies, but everyone thinks they're wimpy -- until The Friz flutters in!

It's the International Show-and-Tell Competition. Arnold brings in a webbed hoop, given by his great-aunt, a famous archaeologist, but what is it?