Thanks to everyone at Bloomsbury, especially Sarah Odedina and Georgia Murray. To Caroline Michel, Suzanne Gluck, and the William Morris team. To Leah Schmidt, at The Agency. To Philippa Brewster and Henri Llewelyn Davies for their detailed reading, and to Lysander Ashton, quantum physicist and film-maker, who checked the science, and to my godchildren, Eleanor and Cara Shearer, who checked the science fiction. To Fiona Shaw who was always Mrs Rokabye as I was writing. And to Deborah Warner for the generous loan of her parents, Roger and Ruth, a house full of antiques, and a sense of possibility.