Book excerpt: The classic Roald Dahl story with fabulous full-colour illustrations by Quentin Blake. George Kranky's Grandma is a miserable grouch. George really hates that horrid old witchy woman. One Saturday morning, George is in charge of giving Grandma her medicine. So-ho! Ah-ha! Ho-hum! George knows exactly what to do. A magic medicine* it will be. One that will either cure her completely . . . or blow off the top of her head. *WARNING: Do not try to make George's Marvellous Medicine yourselves at home. It could be dangerous. Look out for new Roald Dahl apps in the App store and Google Play- including the disgusting TWIT OR MISS! and HOUSE OF TWITS inspired by the revolting Twits. "A true genius . . . Roald Dahl is my hero" David Walliams