The Harold Shea stories are parallel world tales in which universes where magic works coexist with our own, and in which those based on the mythologies, legends, and literary fantasies of our world and can be reached by aligning one's mind to them by a system of symbolic logic. In The Castle of Iron, the authors' protagonist Harold Shea visits two such worlds, first (briefly) that of Samuel Taylor Coleridge's poem Kubla Khan and second that of Ludovico Ariosto's epic, the Orlando Furioso.
