It's time for Ms. Frizzle's class to get ready for the science fair, but brainstorming for ideas has them coming up empty-handed. Luckily for them, no task is too great for their clever and zany teacher! Always eager to embark on another class trip, Ms. Frizzle sends her students around the corner to the Walkerville Science Museum, then takes them on a colossal leap back in time to meet some of science's all-time greats!