I always dream of labyrinths or mirrors. In the dream of the mirror another vision appears, another terror of my nights, and that is the idea of the mask. Masks have always scared me. No doubt I felt in my childhood that someone who was wearing a mask was hiding something horrible. These are the most terrible nightmares: I see myself reflected in a mirror, but the reflection is wearing a mask. I am afraid to pull the mask off, afraid to see my real face, which I imagine to be hideous. There may be leprosy or evil or something more terrible than anything I am capable of imagining.-- from 'Nightmares', in Seven Nights (1980) by Jorge Luis Borges.
What if nightmares were strictly supernatural? What if nightmares were cries from hell? What if nightmares literally took place in hell? Why not? Everything is so strange that even this is possible.