Night's Master by Tanith Lee

A recognized master fantasist, Tanith Lee has won numerous awards for her craft, including the World Fantasy Award for Life Achievement and the Bram Stoker Award for Lifetime Achievement in Horror.
Rediscover her classic, most popular fantasy series, Tales from the Flat Earth, where demons and gods grant wonders and wreak havoc. Visit the Upperearth, where dwell the gods; the Underearth, the realm of nightmarish demons; the Innerearth, domain of the dead; and the Flat Earth itself, the home of mortals.
Supreme amongst them all is the demon god Azhrarn, Night's Master, whose deadly whims could change the lives of those in the Flat Earth. Azhrarn holds in his heart a mystery which could alter the very existence of the Flat Earth forever.
From the Paperback edition.

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