River Into Darkness

For the first time in an omnibus edition, this duology tells the tale of a twilight age for magic, as one ancient mage tries to hide the secrets that might destroy the world. It is the twilight of the mages.... Only one of these terrifying and mysterious men still remains--the difficult and enigmatic Lord Eldrich. More than one hundred and thirty years of age, but appearing no older than forty, Eldrich dwells in seclusion, his precious knowledge disclosed to no one, his very existence subject to speculation.
For motives of his own, he has dedicated his life to eliminating all remaining vestiges of magic in the world. But his work does not go unchallenged: for there are those sworn to preserve the very lore Eldrich is striving to eradicate. Fanatical followers of a long-dead mage-apprentice, the Tellerites will stop at nothing to reclaim the forbidden powers of the magical arts--even if it means braving Eldrich's wrath and descending into the perilous depths of a labyrinthine cave system, in search of secrets that have lain hidden since the time of the first mage.