John W Campbell's "Dead Knowledge" (as by Don A Stuart) (novelette, alien invasion): "Molecular", microscopic, space traveling, light-eating alien invaders want to control us as tools!
Three human star travelers have arrived at a new world 27 light years from earth, only to find that it once harbored intelligent, highly developed, humanoid civilization that is now dead. And, curiously, it's long dead residents have their bodies well preserved & they all apparently committed suicide!!
It drags on for a while, until the visitors themselves start committing suicide - first one, then other. It's the final one who will enlighten us on the nature of infection before himself committing suicide.
Fact sheet.First published: Astounding, January 1938.
Nominated for Retro Hugo Awards 1939 in novelette category.
Among the stories from Astounding/Analog issues edited by John Campbell.
Related: Works of John Campbell (as by Don A Stuart).