The Fellowship of the Talisman — Clifford D. Simak

A strange assortment of humans and otherworldly beings joins a young soldier of God on his perilous quest through an alternate, technology-free reality ruled by an all-powerful Evil

In an alternate world where the Dark Ages never ended, “the Evil” that arises every five hundred years has prevented all manner of technological advancement, even well into the twentieth century. The son of a powerful English noble, young Duncan Standish has always longed to be a soldier of the Lord, and now he's been offered a rare opportunity to fulfill his dream. Entrusted with the delivery of an ancient manuscript -- purported to be irrefutable evidence of the existence of Jesus Christ -- to a noted Oxenford scholar, Duncan must journey many perilous miles in the company of a motley group of fellow travelers, including a goblin, a ghost, and other magical and non-magical companions. But the road they traverse together is fraught with terrible trials that would test even the most devout, for the Evil is strong in this place of dark wonders.
 
Multiple Hugo, Nebula, and Locus Award�"winner and SFWA Grand Master Clifford D. Simak moves easily from science fiction to quest fantasy in this enthralling tale of magic, peril, and discovery on an Earth that never was. Rich in color, thrills, and wild invention, and populated by a highly original and unforgettable cast of characters, Fellowship of the Talisman showcases the author's peerless storytelling skills, demonstrating once again that the great Simak had few equals in the realm of twentieth-century speculative fiction.