From Beyond

"From Beyond" is a horror short story by American writer H. P. Lovecraft. It was written in 1920 and was first published in The Fantasy Fan in June 1934.
The story is told from the first-person perspective of an unnamed narrator and details his experiences with a scientist named Crawford Tillinghast. Tillinghast creates an electronic device that emits a resonance wave, which stimulates an affected person's pineal gland, thereby allowing them to perceive planes of existence outside the scope of accepted reality.
Sharing the experience with Tillinghast, the narrator becomes cognizant of a translucent, alien environment that overlaps our own recognized reality. From this perspective, he witnesses hordes of strange and horrific creatures that defy description. Tillinghast reveals that he has used his machine to transport his house servants into the overlapping plane of reality. He also reveals that the effect works both ways, and allows the alien creature denizens of the alternate dimension to perceive humans. Tillinghast's servants were attacked and killed by one such alien entity, and Tillinghast informs the narrator that it is right behind him. Terrified beyond measure, the narrator picks up a gun and shoots it at the machine, destroying it. Tillinghast dies immediately thereafter as a result of apoplexy. The police investigate the scene and it is placed on record that Tillinghast murdered the servants in spite of their remains never being found.
Famous works of the author Howard Phillips Lovecraft: At the Mountains of Madness, The Dreams in the Witch House, The Horror at Red Hook, The Shadow Out of Time, The Shadows over Innsmouth, The Alchemist, Reanimator, Ex Oblivione, Azathoth, The Call of Cthulhu, The Cats of Ulthar, The Dunwich Horror, The Doom that Came to Sarnath, The Festival, The Silver Key, The Other Gods, The Outsider, The Temple, The Picture in the House, The Shunned House, The Terrible Old Man, The Tomb, Dagon, What the Moon Brings.