Great Master Lawrence:
Sometimes the most obvious things are the most difficult to notice.
Listen carefully. There are numbers mentioned in the beginning of the prayer.
One emperor... 3 pairs of the wings...6 catacombs...7 Necropolises...
That's 1, 6, 6, 7. That's the clue we need to find the book.
How about that? Not to shabby for an old geezer, eh? Ha ha!
"But where is the book?"