ACKNOWLEDGMENTS

I must thank my editor, Nick Sayers, for patience, insight, and steak; my agent, Jemima Hunt; everyone at Hodder, especially Eleni Lawrence and Cicely Aspinall.

Thanks, too, to all the team at Quercus USA, especially Amelia Ayrelan Iuvino, Nathaniel Marunas, Amanda Harkness, and Elyse Gregov.

Thanks to: Saul Dibb, Stephen Guise, and Tom Lyle.

Thanks also to the staff of the British Library, where much of this book was researched. I drew on too many historical sources to name them all here, but I must mention the following: The Defence of the Realm by Christopher Andrews, The Security Service 1908–1945 by John Curry, MI6: The History of the Secret Intelligence Service 1909–1949 by Keith Jeffery, The Quest for C by Alan Judd, and especially The Houndsditch Murders and the Siege of Sidney Street by Donald Rumbelow.

Most of all, I want to thank my family: the wondrous R and E, and my partner Annalise Davis, for her sharp wit, innate wisdom, and inspirational energy.