From the back cover:
The Drow of the Underdark
They are the favorite foes of many a party of adventurers. In these pages, the drow come to life, their culture and powers detailed for the first time. This guide presents new rules galore: new spells, new magic items, insight into the mysteries of Lolth, Monstrous Compendium entries for related monsters of the Underdark- and much, much more.
Learn all about the drow herein, from words of the ancient sage Erlathan Greycloak:
"Proud, graceful evil. Cruelty personified; talent wasted, beauty lost in darkness."
to the lore of Elminster:
"Did I ever tell thee how close I came to having a drow wife? No? Well, then..."