Danny Timmons has looked up to Jack Bailey ever since Jack 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 without a trace 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. As answers elude him, Danny begins to fear that he didn't know Jack as well as he thought.