Ms. Frizzle shrinks her students and takes them on a tour of a rotten tomato and a hamster's water dish in an attempt to prove to Keesha that microbes are responsible for turning a prize cucumber into a pickle.
General Note
At head of title: Scholastic's.
"From an episode of the animated TV series produced by Scholastic Productions, Inc. Based on The Magic School Bus books written by Joanna Cole and illustrated by Bruce Degen"--T.p. verso.