From the #1 internationally bestselling author of How to Train Your Dragon and Wizards of Once comes an out-of-this-world adventure where magic and reality collide! K2 O'Hero is a seemingly ordinary boy--after all, he and his twin sister, Izzabird, have been sworn to keep their family's Magical history a secret. Not even their infuriating stepsiblings, Theo and Mabel, know that 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 imaginations. Worlds with six hundred moons, burning rivers, and dark, twisty jungles alive with plants that hunt by the smell of fear. But what K2 doesn't know is that the maps he draws are real. When their baby sister, Annipeck, is kidnapped, the warring stepsiblings will have to use K2's gift to find a crossing point into one of those worlds and embark on a daring rescue mission.