The one test of the really weird (story) is simply this--whether or not there be excited in the reader a profound sense of dread, and of contact with unknown spheres and powers; a subtle attitude of awed listening, as if for the beating of black wings or the scratching of outside shapes and entities on the known universe's utmost rim.
H. P. Lovecraft, Robert E. Howard (2011). “Mythos: The Myths and Tales of H.P. Lovecraft & Robert E. Howard”, p.14, Manticore Press