A Blackbird in Amber - Blackbird Book 3
Description from the back of the book
The great serpent M'gulfn was dead, its power dispersed and all save one of its demon-servants destroyed.
Now was the time when the power of sorcery might be harnessed for good or for evil.
Journeying disguised to Gorethria came Mellorn, daughter of Silvren and Ashurek, by training and by will eager to use that latent power for good.
But to Gorethria, summoned by the usurper Duke Xaedrek, there came also the demon Ahag-Ga in the guise of an old woman. Together they plan to use the power: he to rebuild the terrible authority of the old empire; she, silently vengeful, determined to unleash the dark forces of Chaos on a world that, saved, is yet in peril.
Condition - good, has signs of aging on the pages and creases on the spine.