immortality

"Okay, I have to establish three things in order for the book to make sense. I have to establish that in this version of Earth, the meme of immortals walking among us already exists, if only as a kook conspiracy theory like the Masons or Illuminati. I have to establish the existence of a lost gospel, an ancient document describing the immortals at the beginning of their myth, and I have to establish the existence of a database of immortal identies through history, proving that these people live forever and just keep adopting new personas.