K2 O'Hero is a seemingly ordinary boy from a truly extraordinary family - he and his twin sister Izzabird have been sworn to keep their family's history of magical explorers a secret. Not even their infuriating step-siblings, Theo and Mable, know magic exists. They believe K2 to be the most hopeless person they have ever known.

But K2 has a secret gift. He draws maps of worlds that are beyond the wildest of imaginations. Worlds with six hundred moons, burning rivers, armoured robots and dark, twisty jungles alive with cannibal plants who hunt by the smell of fear. K2 and his warring siblings are going to have to use this gift to cross over into another world on a daring rescue mission to save the one thing they agree on: their baby sister Annipeck. With a terrible beast and a petrifying robot assassin in their way, they must work together and learn how to be brave - because the future of their family is at stake.

In this episode Gregory Dobbs cats to Cressida Cowell about the way her writing and illustration work hand-in-hand in her creative process, how she brings fantasy and reality together to tell real human stories, and her fascination for magical maps from a very early age.