My thanks to the extraordinary patience of my editor, Paul Elie, to whom this book owes its existence, and to Paul Richard Blum, Lina Bolzoni, Eugenio Canone, Donald Carroll, Thomas Cerbu, Maria Ann Conelli, Jon Cooper, Brian Copenhaver, Karen de León-Jones, Germana Ernst, Mordechai Feingold, Jonathan Galassi, Anthony Grafton, Dario Ianneci, James Kalsbeek, Eugenio Lo Sardo, John Marino, Peter Mazur, Mario Pereira, Dana Prescott, Pasquale Siciliani, Robert Silvers, Frank and Margaret Snowden, Joanne Spurza, Daniel Stein-Kokin, Haris Vlavianos, and the Libreria ASEQ in Rome, where Edoardo and Luca have kept me supplied with books on or by Giordano Bruno for nearly three decades. Thanks also to the Biblioteca Apostolica Vaticana; the Biblioteca Casanatense, Rome; the Biblioteca Angelica, Rome; the Biblioteca Nazionale Centrale, Rome; the Biblioteca Nazionale, Naples; the Archivio di Stato, Venice; the Herzog August Bibliothek, Wolfenbüttel; the University Library, Cambridge; the Bodleian Library, Oxford; and the British Library. Fellowships from the John Simon Guggenheim Foundation, the Rockefeller Foundation Study Center at Bellagio, and the Getty Research Institute facilitated research and writing at various stages; at Bellagio, my particular thanks to Gianna Celli, now director emerita; at the Getty Research Institute, to Michael Roth (now president of Wesleyan University), Charles Salas, Susan Allen, Wim DeWit, and the entire Department of Special Collections. The library of the great Bruno scholar Frances Yates, now owned by the Getty Research Institute, provided extraordinary tangible inspiration. Thanks to my superb copy editor, Ingrid Sterner, for saving me from an infinite universe of lapsus calami. I owe thanks of a different kind to my parents: to my father for his broad view of science and to both of my parents for their example of unflagging integrity. The late Father Athanasius Kircher, S.J., read Giordano Bruno faithfully when it was still dangerous to do so, and despite the centuries that divide us, he had, like the other people and institutions here enumerated, more than a minor role in the shaping of this book. Above all, my thanks to the two people to whom it is dedicated: Hilary Gatti, infallible guide to the intricacies of Bruno’s thought, and Avvocato Dario Guidi Federzoni, who revealed the legal thriller latent in a tragedy.