Hattie Owen enjoys peaceful Millerton summertimes with houses nodding in the heavy air, being in charge of Miss Hagerty's breakfast tray at her parents' boardinghouse, and drinking lemonade on the porch after supper. Yet this year, it's different -- Hattie's uncle Adam is coming home. Returning from a Chicago school that's just closed and whose existence is kept quiet by adult family members, Adam is a 21-year-old man with a child's mind, having a knack for talking quickly, a savant-like ability for remembering weekdays, and a passion for I Love Lucy. Hattie and Adam wind up spending precious time together -- including a visit to the recently arrived carnival with Hattie's new friend, Leila -- which makes her feel soulfully connected to her uncle, especially when he declares that she's one of the people who can lift the corners of our universe. But when Hattie takes Adam on the Ferris wheel one night, it sets off dramatic events that lead Hattie's family to strengthen its bonds and changes her life's outlook forever.