Thrilling Wonder Stories April 1941 — Tiny Alien Gunman Terrorizes Subway Riders

Predicting neither smartphones nor miniaturization tech accurately, this cover imagines the real threat of the future as a glowing, fist-sized alien creature brandishing a ray gun at bewildered commuters on what appears to be public transit. A blonde woman in red recoils, a man in a fedora gapes, and a body already lies slumped on the floor — all victims of this pint-sized extraterrestrial menace emanating from a luminous energy sphere. Pure Golden Age paranoia rendered in vivid gouache.