When the Changewind Blows — Jack L. Chalker

SHE WAS HAUNTED BY THUNDER AND PLAGUED BY DREAMS...strange, dark dreams of a world beyond time and space, a land of magic and mystery. But Charley knew it was more than a dream---for her friend Sam shared her vision.

SUDDENLY, THE DREAMS BECOME A REALITY...as a raging storm sweeps Charley and Sam to the fantastic land of Akahlar, where unicorns and griffins run free, an enchantress commands a den of unearthly pleasures, and a wizard warns of a terrifying inescapable event:

THE CHANGEWINDS ARE COMING...savage, purple-tinged storms that alter the shapes of man and beast alike. Soon, all creatures must look to the skies---and beware...