The Book of the Old Time
The Book of the Old Time was an ancient book of great import, kept on Gallifrey.
The Book contained sacred star-charts belonging to Voyager, a timeless Lord of Life, which had been stolen from him by "the Time Lords". The Sixth Doctor speculated that Voyager and his Death-ship had visited the dreams of Rassilon in past aeons. At any rate, the Book was stolen by Astrolabus, a Time Lord who had once been a great explorer (having mapped out the first meridians of Time), for which crime Astrolabus was banished from Gallifrey. However, he took the charts with him. (COMIC: Voyager)
However, the Book's contents remained known; it spoke of Rassilon's retrieval of the naked singularity later known as the Eye of Harmony. By the Doctor's time it had acquired the status of an ancient, cryptic text, the meaning of which no one understood. (TV: The Deadly Assassin) It was his encounter with the book that had first nudged the Doctor's thoughts towards Gallifrey's ancient history. He began to suspect that before regeneration, there had been reincarnation. (PROSE: Cat's Cradle: Time's Crucible)
Meanwhile, Voyager pursued Astrolabus for the star-charts to the very edge of the universe. After Astrolabus managed to escape one more time in the presence of the Sixth Doctor, Astrolabus told the Doctor to hunt down Astrolabus on his behalf, as he held all Time Lords responsible for the theft. (COMIC: Voyager) To secure his permanent ownership of the charts, Astrolabus ultimately had them tattooed on his skin, only for Voyager to flay him alive with a sandstorm he summoned, thus taking back the forbidden knowledge. (COMIC: Once Upon a Time-Lord)
A Time Lord author remarked in his studies of Gallifreyan history that no one was quite sure when the book was written while suspecting that it was only written as a way for Rassilon to ensure he would be remembered. (PROSE: A Brief History of Time Lords)
