Clifford D. Simak 
Where the Evil Dwells [EPUB ebook] 

The renowned Science Fiction Grand Master makes a foray into fantasy, with this tale of perilous adventure in a land of trolls, wizards, and terrifying malevolence. In an alternate Europe where the Roman Empire never fell, the expansive Empty Lands are inhabited by forces known collectively as the Evil. Yet Charles Harcourt is honor-bound to venture into that dangerous area to find his long-lost fianceé. He is joined on his trek by an abbot who hopes to locate a crystal prism that hold the soul of a saint; the non-human Knurly Man, who craves release from his pitiful existence; and the beautiful Yolanda, who seeks the answer to a secret mystery. But their arrival and their purpose had been foretold. The denizens of the Empty Lands are girding for war. And beyond the Evil lurk ancient dark powers waiting patiently for the humans whose souls will set them free.