Unholy

The realm of Thay is more war-torn than ever—but its surviving citizens are game for one final battle against the evil necromancer Szass Tam
 
The formerly green fields of Thay lie in war-torn ruins and the realm’s formerly living populace is undead. With the mageocracy in exile, masters of no more than their beaten army, they watch from distant shores as Thay continues to descend into chaos.
 
Meanwhile, the brilliant necromancer-turned-King of Thay—the mastermind behind the civil war that drove the ruling council into exile—appears to have gone insane. But rumor soon spreads of a reason behind his erratic behavior: a great magical ritual. As Szass Tam moves forward with his villainous plot, the survivors of the realm must band together to prevent him from destroying not just Thay but the entire world.