Supernatural fiction contains its own generic borderland: a neutral territory, which Tzvetan Todorov calls 'the fantastic,' between 'the marvelous' and 'the uncanny.' According to Todorov, 'The fantastic is that hesitation experienced by a person who knows only the laws of nature, confronting an apparently supernatural event.' Once the event is satisfactorily explained (and sometimes it is never explained), we have left the fantastic for an adjacent genre - either 'the uncanny,' where the apparently supernatural is revealed as illusory, or 'the marvelous,' where the laws of ordinary reality must be revised to incorporate the supernatural. As long as uncertainty reigns, however, we are in the ambiguous realm of the fantastic.
In any event, whether a supernatural tale remains altogether fantastic or eventually modulates to the uncanny or the marvelous, the reader is faced with disconcerting ontological and perceptual problems.Indeed, the disorienting effect of the supernatural encounter in fiction seems to reflect some deeper disorientations in the culture at large.
We are aberrations—beings born undead, neither one thing nor another, or two things at once … uncanny things that have nothing to do with the rest of creation, horrors that poison the world by sowing our madness everywhere we go, glutting daylight and darkness with incorporeal obscenities. From across an immeasurable divide, we brought the supernatural into all that is manifest. Like a faint haze it floats around us. We keep company with ghosts. Their graves are marked in our minds, and they will never be disinterred from the cemeteries of our remembrance. Our heartbeats are numbered, our steps counted. Even as we survive and reproduce, we know ourselves to be dying in a dark corner of infinity. Wherever we go, we know not what expects our arrival but only that it is there.
In telling a story one of the most successful devices for easily creating uncanny effects is to leave the reader in uncertainty whether a particular figure in the story is a human being or an automaton and to do it in such a way that his attention is not focused directly upon his uncertainty, so that he may not be led to go into the matter and clear it up immediately.
Gerbert, by the window, shuddered; his mouth contorted. The witch began to twist faster and faster while her twin was talking to Gisela, mumbling to her, marching old holy words straight through the child’s ear into her skull, where they entered the bloodstream and looked for the enemy. The monk’s fingers twitched in the same rhythm and he found himself falling into a trance. He knew it would be dangerous to witness the witches brewing and dancing but there was an energy in it that he’d missed badly since he’d been asked to educate the young princess. Gerbert didn’t even notice when the hags stopped, tucked the girl in, rubbed the concoction on her lips and left for the unseen place from which they had come. Gisela healed quickly thereafter: The fever fell that same night and she asked for solid food the next morning. She had no memory of what had happened, but when she bounced on one leg across the meadow in the castle yard, she chanted a little melody that had not been heard in church, an odd melody that made Gerbert’s ears prick up because he sensed the uncanny in it.