Hugh Welch has cared for his little sister Dorsey ever since they were children, when Dorsey looked at him as though he were a god. But when Dorsey returns to their small Michigan hometown with a successful career as an astrophysicist and a happy family life, Hugh, who has a long habit of worrying about his sister, realizes that it's his own life he has to cure, not Dorsey's. As they explore their complicated history over one hot Fourth of July weekend, they'll come to terms with the experiences that put such distance between them and discover the imperfect love that ties them as siblings.