The Call from Beyond

Story, first published: Super Science Stories, May 1950

In ... "The Call from Beyond" ..., scientists working in a laboratory on Pluto to develop controlled mutations of humans let aliens in from other dimensions; they strongly resemble the scary Cobblies in "City". The story also implies that someone in Atlantis eons ago had made the same mistake. Aliens explain the presence of supernatural beings like ghosts, goblins, incubi, imps, and other such "things that go bump in the night." Simak would develop this idea with much more humor eighteen years later in "The Goblin Reservation".

Ewald, Robert J.: When the Fires Burn High and the Wind is from the North, p.28