Every year, the Levin children spend the summer at their grandmother's historic island home. But this year, Blair, the oldest sister, is pregnant with twins and unable to travel from Boston. Middle sister Kirby is caught up in civil rights protests. And Tiger, the only son, has just been deployed to Vietnam. Thirteen-year-old Jessie, the youngest, is marooned in the house with her out-of-touch grandmother, who is hiding secrets of her own. As the summer heats up, Teddy Kennedy sinks a car in Chappaquiddick, man walks on the moon, and Jessie and her family experience their own dramatic upheavals.