Aqui está uma citação de O Livro de D'ni :
Atrus looked up at the night sky, wondering, not for the first time, just when he was. From his studies of the star charts in the observatory, he had worked out that he was in a very different part of the galaxy from the planet he knew as Earth—or its equivalent—if one even existed in this Age. But it was more difficult to tell just how far he was from it in time, for when one linked there were no limits. The mind-staggering vastnesses of Time and Space were irrelevant. Congruity —the matching of word and place—was all that mattered.
Or, as his grandfather, Aitrus, had explained it to his grandmother, Anna: “These Ages are worlds that do exist, or have existed, or shall. Providing the description fits, there is no limitation of time and space. The link is made regardless.”
A implicação da citação é que Atrus acredita que os livros se ligam a um mundo diferente na mesma galáxia, mas não necessariamente contemporâneo. Mais tarde, no romance, um antigo livro de encadeamento é encontrado e, através de experimentos, os personagens deduzem que ele vincula a um mundo cuja estrela tem foi supernova e destruiu o mundo.