All brightness was gone, leaving nothing. We stepped out of the tent onto nothing. Sledge and tent were there, Estraven stood beside me, but neither he nor I cast any shadow. There was dull light all around, everywhere. When we walked on the crisp snow no shadow showed the footprint. We left no track. Sledge, tent, himself, myself: nothing else at all. No sun, no sky, no horizon, no world.
Ursula K. Le Guin, The Left Hand of Darkness
science-fiction, setting