All the adults are freaking out. Giant monsters are smashing up supermarkets across the country. The army can't stop them and the prime minister is hiding in panic. A colossal six-headed gingerbread man, a massive emoji poo, a gigantic bouncing bum. Top scientists have no idea where they come from - or why they seem to hate supermarkets so much. But nine-year-old Otis has an idea. The creatures are exactly the same as drawings by his five-year-old brother, Jago: what if Jago brought his crazy creations to life with a magic pen? But their parents won't listen, so it's up to Otis and his pals to sort this monster mess out!