I have hijacked my own website here, replacing the original one with a drastically generalized version of the same idea. When created, this site was about an imaginary series of books which were supposedly written by a character in a novel. The generalization is to stories which appear within other stories.
The classical example of this is a book called The Thousand and One Nights in which Scheherazade tells the Persian king Shahryar a series of tales, one per night, so that her life might be spared. Though these stories were mostly separate tales later assembled into book form, they are stories within the overall story of a woman saving her own life by turning storyteller. There are actually several versions of the book, with the same unifying theme.
Stories within stories are a major part of our culture. Various Greek myths and legends appear in different books. Various books tell stories of King Arthur and his knights. Some of these stories are just about famous knights, and may have been grafted onto the King Arthur legend.
With Chaucer’s Canterbury Tales are several embedded stories, all independent.
Some stories are not intentionally different.
Perhaps the most difficult and controversial of example is given by the Gospels of the New Testament. They each tell a story, but not exactly the same story.
Much argument and much serious academic work has gone into untangling the actual narrative or underlying history.
Another example of interest is that of the Greek philosopher and mathematician Pythagoras. None of his writings survive and he is known only from secondary or tertiary sources.
Is he gone? Are the original words of Pythagoras lost forever? Is there a true history of Jesus Christ, if he existed at all? What about King Arthur and his knights?
I think that what Classical scholars have long tried do with Greek and Roman authors does show steady progress. Though highly controversial, I think that Biblical scholars are getting somewhere. Our cultural past is not lost forever.
But what humans can do is probably insignificant compared to what will be possible when the results of Very Large Collection of Social Data are used in literary studies. This is described on my website which deals with the use of this data in the analysis of books.