The Mad Moon

As did his earlier stories "A Martian Odyssey" and "Parasite Planet", "The Mad Moon" emphasizes Weinbaum's alien ecologies.

It is the 22nd century[1] and protagonist Grant Calthorpe is a former sport-hunter collecting ferva leaves for the Neilan Drug Company, living near the Idiots' Hills with a parcat named Oliver.

In a narrow valley between two peaks, they find a deserted city, apparently built by more-civilized previous generations of loonies.

Io, the innermost Galilean satellite, has a tropical climate, so that two human settlements are located at the poles, Junopolis in the north and Herapolis in the south.

Ionan flora includes ferva leaves, used by pharmaceutical companies on Earth to create alkaloids; bleeding-grass, which exudes red sap; and stinging palms, named for venomous barbs.