Many thanks to Tor.com for giving the Gemworld its proper setting. To my editor, Patrick Nielsen Hayden, and to Irene Gallo, for their vision; to Lee Harris, Mordicai Knode, Tommy Arnold, Anita Okoye, Rachel Bass, Lauren Hougen, and Ana Deboo.
To Paul Race and to Chris Wagner, who let me mess about with metals, stones, and oxygen-acetylene torches. To my first library, Tredyffrin, and to many of my favorites, including the Peabody, Trinity, the Enoch Pratt, the Library of Congress, the Bodleian, Northwest Akron, the Alderman, the New York Public Library, and the Free Library of Philadelphia. To all the librarians and timekeepers in my life, friends, family, and those I’ve met in the stacks.
To E. Catherine Tobler, Kelly Lagor, Nicole Feldringer, Chris Gerwel, Lauren Teffeau, Aliette de Boddard, Ryan Labay, Lynne M. Thomas, Siobhan Carroll, A. T. Greenblatt, Sarah Pinsker, A. C. Wise, and my agent, Barry Goldblatt, who were all very patient with facets of this story.
To everyone who loves books, or time, or who knows that a little bit of time travel happens whenever a page (or a phrase) is well turned, this is for you.