Warfare is becoming increasingly a matter of scientific cleverness and power. A nation of 100,000,000 people, who had no arms other than shotguns would be at the mercy of an enemy many times smaller who was armed with the latest of killing devices.

Scientific ingenuity for warfare has been turning lately to the development of little known biological devices. In this field there is almost no limit to the fiendish contraptions to make warfare a hell on earth. This tale is a case in point, with a startling and surprising climax.

This classic short story, by the author of The Day of the Triffids and The Midwich Cookoos (filmed as Village of the Damned) originally appeared in Wonder Stories magazine in 1933.

Includes an introduction by Karl Wurf.