The class has decided to give Ms. Frizzle a present for Earth Day--a cocoa bean tree in the Amazon Rainforest, as cocoa beans are used to make chocolate. The day just happens to be the one when the first shipment reaches them, but for some reason, the tree has produced none. They go to the rainforest to find the reason and Ms. Frizzle makes Tim and Dorothy Ann "RFIs," or Rainforest Investigators. The tree is in a patch of the rainforest controlled by Inspector 47 (Matt Frewer), who talks with a strong accent and runs around the rainforest in a white suit. He is very proud that he got rid of the mud in his patch, however, the class finds out, at the end, that the mud's absence was what caused that of cocoa beans. The mud holes were where the insects that pollinated the cocoa pods lived, and it is revealed that Inspector 47 had covered the rainforest floor with artificial turf! They explain this to him and he decides to "rip up this filthy artificial turf with my bare hands".
