With the aid of some henchmen, he's began infecting the world: sending up balloons to release these spores. He intends to be world dictator.
Johnny Black, an intelligent bear being trained by Prof Methuen, will discover the conspiracy, but only after all humans in the lab he's at have been infected. It's now up to him to revive some humans...
Fact sheet.First published: Astounding, October 1938.
Among the stories from Astounding/Analog issues edited by John Campbell.
Related: Stories of L Sprague de Camp.