"The Nine Princes in Amber" is the first book in the Chronicles of Amber series by Roger Zelazny. It follows the story of Corwin, a prince of the royal family of Amber, who awakens in a hospital with amnesia. As he regains his memories, he learns about the existence of Amber, the true world, and its shadow worlds, including Earth. Corwin discovers that he is embroiled in a power struggle among his siblings, each vying for the throne of Amber. The novel explores themes of family, betrayal, and the nature of reality as Corwin navigates the complexities of his royal lineage and the magical abilities that come with it.