Note: On the Sphere edition's copyright page the author writes: "Fool's Hill was published in the United States under the title The Crack in the Sky. That title was imposed by my American publishers over my objection. The change was made for commercial reasons, and while I was not pleased, I could not complain too loudly: they were doing their best to sell books, which is the way both publishers and authors survive. My British publishers, however, suggested the restoration of the original title Fool's Hill. For reasons inherent in the novel, I consider this the correct title. This correction of a flaw not of their making represents not merely a courtesy on the part of Sphere Books and my editor at Sphere. Mr Nick Austin, but also a restoration of the integrity of the book."