Emair continues, still calmly.
"As to its purpose, I suppose I could offer this explanation if it will placate you: Xargon scribed a powerful spell upon the book. Think of it as a scroll, of a very advanced order. The spell itself is one of the things that helps render Xargon 'immortal.' I wish to retrieve the book on behalf of Xargon and return it to him so he may continue defending the empire against the giants. This tower you've opened for a second time is his property. For lack of a better term, think of Glukma and myself as his proxy in this matter."
Can I get a Bardic Knowledge roll on this? 13+6=19
Xargon is a near-mythical figure (think "Odysseus") which probably had some basis in history. Legends abound regarding his heroic efforts at the founding of the Empire and was purported to be a friend or at least an acquaintance of Kazak the Conqueror.
Most stories regarding Xargon indicate his forays were primarily against the giants of Jotunland and he helped establish a northern border hedging the giants out of the Empire. His signature weapon was a flaming spear, endowed with different enchantments, depending on whose telling the tale.
Primarily in the south, in the modern Empire, Xargon has taken on something of a boogeyman role, used in morality stories and fairy tales to frighten children. "Stay quiet or Xargon will find you tonight."