Henry Kuttner 
The Dark World (with linked TOC) [EPUB ebook] 

World War II veteran Edward Bond’s recuperation from a disastrous fighter plane crash takes a distinct turn for the weird when he encounters a giant wolf, a red witch, and the undeniable power of the need-fire, a portal to a world of magic and swordplay at once terribly new and hauntingly familiar. In the Dark World, Bond opposes the machinations of the dread lord Ganelon and his terrible retinue of werewolves, wizards, and witches, but all is not as it seems in this shadowy mirror of the real world, and Bond discovers that a part of him feels more at home here than he ever has on Earth. Dark World was a profoundly influential novel. It’s mixture of science and fantasy inspired Roger Zelazny to write the Amber Chronicles. Marion Zimmer Bradly said that every novel she had ever written was because she had read Kuttner.