I would first like to thank several people for reading and commenting upon the manuscript through its several drafts: my agent, Dominick Abel; Cynthia Good, from Penguin Books Canada; Natalee Rosenstein, from Berkley; and my copy editor, Mary Adachi. I would also like to acknowledge expert help from a variety of sources. Thanks, as ever, to Detective Sergeant Keith Wright, of Nottingham CID, who answered my frequently silly questions with his characteristic patience and humour. Thanks also to Pamela Newall, from the Centre for Forensic Sciences, for saving me from sounding like a complete idiot on DNA, to Paul Bennett for reading and commenting on the trial scenes, to John Halladay for further information on legal procedure and to Dr Marta Townsend for the displacement.