Explain the author's use of foreshadowing in Nadine Gordimer's "Once Upon a Time

Nadine Gordimer meshes numerous cases of portending into "Quite a long time ago." The casing story presents the idea of dread. The possibility of the underground mining burrows that stone the storyteller's home-dull, imperceptible, and enigmatic-hint the ethnic turmoil that stones the social texture of the rural group in the sleep time story.