With thanks to my amazing agent, Lauren Abramo, and her awesome London representative, Anna Carmichael. I’m extremely lucky to have such a talented editor in Harriet Wilson; all the thanks too to her. Where would I be without Harriet’s alchemy? Further gratitude is due to Julia Sanderson, Sean Williams, and everyone else at HarperCollins Children’s. I’m also extremely grateful to the Society of Authors. Their grant enabled me to journey across America, albeit without missing any flights.