Alexandria Eternal. Very simply...
What came first? The City or the Library? In this case, why not the latter. A library that constantly grows, and within it, books that have the lives of everyone who has ever lived. And as people continue to live, their stories are continued to be written. To alter the story in the book however... changes the very nature, nay, history of that person.
The stories of humanity. Hidden away. Kept in secret.