Voren'thal the Seer in Shattrath City wants you to obtain an Arcane Tome.
Performing quests for the Scryers will cause your Aldor reputation to decrease.
Arcane tomes are not ordinary books that happen to deal with arcane matters. There is intrinsic power in them - a power I've learned to synthesize into a single arcane rune.
Should you find an arcane tome in your travels I will give you one such rune. Only the most powerful wielders of magic carry the books I need. In Outland this usually means Kael's blood elves - but you'd be surprised by where such tomes often turn up.