A white girl disappears from a white prep school in a white suburb. Nobody knows what happened to her. The overall whiteness of the world is threatened. This must be resolved by whatever means possible.
I don't think fake people living in a fake house in a fake suburb are any less dismissible or believable than a fake psychic attending a fake school in a fake town. Nothing's inherently believable about any kind of fiction, because all of it's untrue.
