From the publishers website:
"Having annihilated the Giant Prince Snorre, it was discovered that the drow were the instigators of the uprising. After a fierce fight, the cowardly dark elves have retreated into the NetherDeep and it is up to your players to go down and destroy them on their home turf. Strange creatures unseen on the surface world populate its darkened caves and warrens. Certainly peril lies ahead for only the most savage of creatures (and luckiest of players) can survive in the dreary depths!"