Demon Lord of Karanda

From the flaps of the Del Rey first printing: "Captives of His Imperial Majesty - Zandramas had stolen King Garion's infant son and fled far to the east, there to use the child in some ritual that would make the Dark Destiny supreme. Garion and his friends had followed, but now they were captives of Zakath, Emperor of Mallorea, taken to his capital city of Mal Zeth. There they were treated almost as friends and surrounded in luxury. But Zakath stubbornly refused to let them leave. Meanwhile a man called Mengha was leading a horde of demons to ravage and conquer the cities through which they must travel. Zandramas was escaping further toward her goal. And the Seeress of Kell revealed that they must be at the ancient palace of Ashaba within a matter of days or Zandramas would win by default. Then a horrible, fatal plague struck the city of Mal Zeth, closing it against all traffic in or out..."