Annihilation

Annihilation is the fifth book in the War of the Spider Queen series.

"Menzoberranzan in Ruin.

For enemies of the drow, it would be the ultimate triumph. If the City of Spiders were to find itself buried by the uncaring sands of eternity, thousands would dance upon its grave, including more powerful enemies than even its most suspicious inhabitants have ever imagined. But Gromph Baenre, Archmage of Menzoberranzan, will not let that happen. When the time comes, he will risk everything to save a city and a civilization he loves more than any drow would ever admit.

While Menzoberranzan fights for survival, a dwindling company of would-be saviors travels the multiverse in search of a goddess who could be dead, or could have simply turned away from them. They might just survive the trip, but can they possibly survive the Demonweb Pits?"