The books says that if a man dies at birth and another at a high age or if another dies at a fetus stage it s logical that another is immortal.
In the show they talk about a secret cult who is destroying all the books because no one should here about this , the cult is considered to be today s man in black or something like that and they are mention in books from early years
The book is from 1500 the author is a monk I belive.
This is part 1, there is a second part to this story
