Danny Timmons has looked up to Jack Bailey ever since the older boy saved two small children from drowning during the Great Flood of 1940. Now, with his father away fighting in World War II and his mother about to have a new baby, Danny relies on Jack’s friendship and guidance more than ever. So when Jack goes missing from their small Appalachian town, Danny is determined to find him. He wonders if Jack’s abusive father could be behind his disappearance, or if it has anything to do with Yonder—a hidden magical town Jack once spoke of, where flocks of rainbow birds fly through the sky and they’ve never heard of war. Eventually, Danny’s investigation forces him to reckon with even larger questions: What is America fighting for in this war? What role do each of us play in stopping injustices, big and small? And is there such thing as a true hero?