From the product webpage/inside cover:
Evil is awakening in the world. The Seven Avengers, also known as the Seven Black Generals, are trying to get the mighty Guardian Sword Naterah, The Night Guardian, the legendary blade used by Draman The Red to split the soul of the evil god Zadrak. The Sword is the only thing that can prevent the reunification of his dark soul. Each black General hosts a piece of the soul of Zadrak and they are now slowly awakening to hunt the mighty artifact. The first black General reunited the Zenith tribes to form a barbarian horde. He attacked the western kingdom and tried to destroy the legendary fortress of Draman Del. But a group of heroes activated old traps set up by the archmage Gadrath The Immortal and stopped the advancing horde. Finally, General Adran arrives with an army of Draman and Nath warriors to baulk the Zenith army in Draman Del.
From the back of the book:
The Twenty Sides Of The Evil, the long-awaited sequel of The Legend Of The Steel General.
This new adventure will take the PCs through Arthad and will end in the ominous city of Nath Rex, the heart of the Nath kingdom.