Nine Princes in Amber (1970) by Roger Zelazny, 175 pages
Amber, the one real world, wherein all others, including our own Earth, are but Shadows. Amber burns in Corwin's blood. Exiled on Shadow Earth for centuries, the prince is about to return to Amber to make a mad and desperate rush upon the throne. From Arden to the blood-slippery Stairway into the Sea, the air is electrified with the powers of Eric, Random, Bleys, Caine, and all the princes of Amber whom Corwin must overcome. Yet, his savage path is blocked and guarded by eerie structures beyond imagining; impossible realities forged by demonic assassins and staggering horrors to challenge the might of Corwin's superhuman fury.' to 'Awakening in an Earth hospital unable to remember who he is or where he came from, Corwin is amazed to learn that he is one of the sons of Oberon, King of Amber, and is the rightful successor to the crown in a parallel world.