Sally Nicholls grew up in Stockton-on-Tees and after school traveled the world, working for a period at a Red Cross hospital in Japan. Sally's first novel, Ways to Live Forever, won the Waterstones Children's Book Prize, and she has been shortlisted for the Guardian Children's Fiction Prize, the Costa Children's Book Award, and the Carnegie Medal twice. She lives in Liverpool with her husband and two sons.

Júlia Sardà is an artist who has illustrated many books for children, including The Liszts by Kyo Maclear and Mary Who Wrote Frankenstein by Linda Bailey. Her work has been published around the world in many languages. She lives in Barcelona, Spain.