Eu acredito que a história pode ser O Mundo e Thorinn por Damon Cavaleiro.
Resumo da revisão da KirkusBooks :
Damon Knight’s tale of a teenager forced on a journey downward through a well into underground worlds that are both dangerous and exotic makes for an entertaining read. Blending science fiction and fantasy with boy scout level survivalism, it gradually unfolds a story much bigger than Thorinn’s personal adventures.
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Thorinn, which means “flea,” is young human living on the surface of his world in a giant basin with a huge cylindrical formation that reaches to the top of the sky. Having been raised by an adoptive father, the lame orphan hops around on his one good leg – hence his name. Life is quiet and pastoral until one day when the well runs dry.