Atmosphere, not action, is the great desideratum of weird fiction. Indeed, all that a wonder story can ever be is a vivid picture of a certain type of human mood. The moment it tries to be anything else it becomes cheap, puerile, and unconvincing. Prime emphasis should be given to subtle suggestion - imperceptible hints and touches of selective associative detail which express shadings of mood and build up a vague illusion of the strange reality of the unreal. Avoid bald catalogs of incredible happenings which can have no substance or meaning apart from a sustaining cloud of color and symbolism.

Notes On Writing Weird Fiction