"And then I forgot about everything. Over the pile of old refuse, over broken glass and rags, crawled a shimmering, a trembling, sort of like hot air at noon over a tin roof. It crossed over the hillock and moved on and on toward us, right next to the pylon; it hovered for a second over the road – or did I just imagine it? – and slithered into the field, behind the hushes and the rotten fences, back there toward the automobile graveyard."
"Roadside Picnic", Arkady and Boris Strugatsky