A Nebraska tornado swept away their mother when Leni was nine and her sister Amelia was twelve. Though bound together by tragedy, the sisters grow apart-Leni wrapping herself in silence and solitude while Amelia craves the chaos of a large, close-knit family. Following their different paths, Leni becomes a librarian and Amelia marries into the large family she always wanted. Concerned with her sister's narrow small-town life, Amelia insists that Leni join her husband's family at their New Hampshire lake house for a massive Fourth of July reunion. Over the long weekend, a stifling heat wave...