What cannot be worked through at the conscious level is often worked through at the unconscious level, in dreams and fantasy. cf. Carl Jung (CW 5, para 4-45). When encountering that which we cannot dream, we confront the limits of sense.
Film and art may present an unconscious attempts to work through collective transformation at the limits of reason and sense. In zombie movies and the growing zombie apocalypse movement, we may be seeing an attempt to dream ‘apocalyptic’ change.