Even if the barrier now should disappear and the Flowers withdraw their attention from our Earth, we still would have been shaken from the comfortable little rut which assumed that life as we know it was the only kind of life and that our road of knowledge was the only one that was broad and straight and paved.
There had been ogres in the past, by finally the ogres had been banished. The trolls and ghouls and imps and all the others of the tribe had been pushed out of our lives, for they could survive only on the misty shores of ignorance and in the land of superstition. Now, I thought, we’d know an ignorance again (but a different kind of ignorance) and superstition, too, for superstition fed upon the lack of knowledge. With this hint of another world—even if its denizens should decide not to flaunt themselves, even if we should find a way to stop them—the trolls and ghouls and goblins would be back with us again. There’d be chimney corner gossip of this other place and a frantic, desperate search to rationalize the implied horror of its vast and unknown reaches, and out of this very search would rise a horror greater than any the other world could hold. We’d be afraid, as we had been before, of the darkness that lay beyond the little circle of our campfire.
Clifford D. Simak