All know that Elves cannot die, and that Men do. All know that Men go unto the Underworld upon their death, and that the Elves retire unto the Spiritual Elysium. Yet in the Great Scheme, where goes the one with one foot in the Underworld, and one foot in the Realm of Spirit?
It looks like a cook's book. It is a cook's book. It is also where the cook, who happened to be a master spy, encoded all his secrets and contacts. The book has innocently fallen into your group's hands. Everyone wants it, and many are not subtle or peaceful in their attempts.