David Walliams, hailed as "the heir to Roald Dahl" by The Spectator, burst onto the American scene with the New York Times bestseller Demon Dentist. Now the UK´s #1 bestselling children´s author is back with this high-flying adventure about a boy and his grandfather, perfect for fans of Jeff Kinney and Rachel Renee Russell. Grandpa is Jack´s favorite person in the world. It doesn´t matter that he wears his slippers to the supermarket, serves Spam a la Custard for dinner, and often doesn´t remember Jack´s name. But then Grandpa starts to believe he´s back in World War II, when he was a Spitfire fighter pilot, and he´s sent to live in an old folk´s home run by the sinister Matron Swine. Now it´s up to Jack to help Grandpa plot a daring escape!