The Stolen Bacillus ♦ By H. G. Wells

Wells' short story depicts the interaction between a ostensibly absent-minded bacteriologist who invited a curious stranger to his lab. After showing him stained image under the microscope, the stranger inquires about live samples of the bacterium. When the bacteriologist shows him the "pestilence imprisoned," the inner monologue of the stranger reveals he plans to poison London's drinking water; it is suggested that the visitor is a foreign anarchists.

The visitor excuses himself, leading the bacteriologist to notice the live sample of cholera has gone missing. A brief chase through the city ensues, only to have the now revealed anarchist swallow the sample and begins "jostling his infected body against as many people as possible,"

Though he is at first terrified at the sight, the bacteriologist quickly realizes what he said was Asiatic cholera was in fact another species of the bacteria that has proven to turn hosts blue (a kitten and a puppy) and not cause any pathogenic effects.