Contains four episodes that follow Ms. Frizzle and her class on their science adventures aboard the magic school bus, including a dive into oceans and wetlands.

Gets lost in space (topic: the solar system); Arnold's know-it-all cousin gets Ms. Frizzle's class lost in outer space. Out of this world (topic: space rocks): When an asteroid heads straight for the school, Ms. Frizzle arranges a field trip into space. Gains weight (topic: gravity): Ms. Frizzle takes the class into space and turns the bus into a planet with adjustable gravity. Plays ball (topic: forces): Ms. Frizzle combines physics and baseball...

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.