Ross Montgomery is the author of the picture books Space Tortoise, which was nominated for the Kate Greenaway medal and selected as one of the Guardian's best new books for children 2018, and Building Boy, both illustrated by David Litchfield, as well as the middle-grade fiction titles, Max and the Millions and Christmas Dinner of Souls, both also with illustrations by David Litchfield. His debut novel, Alex, the Dog and the Unopenable Door, was nominated for the Costa Children’s Book of the Year and the Branford Boase Award. It was also selected as one of The Sunday Times' “Top 100 Modern Children’s Classics”. His books have also been nominated for the CILIP Carnegie Award. Find him online at rossmontgomery.co.uk and on Twitter as @mossmontmomery. Sarah Warburton is an illustrator best known for her work on the Princess series by Caryl Hart, the Twinkle series by Katharine Holabird, and the bestselling Dinosaurs in the Supermarket, Dinosaurs in my School, My Adventure Island and Pirates in the Supermarket, all by Timothy Knapman, and Daddy Lion's Tea Party, Man and the Won't Go To Bed Show, and Mabel and Me all written by Mark Sperring. Find her online at sarahwarburtonillustrations.co.uk and on Instagram as s_warburton_ish_