City girl Henri spends the summer of 1986 with her three cousins, the Savages of Bottle Lake. Henri learns to navigate the mountain life while staying one step ahead of the ruthless ranger scouts. The Savages initiate their stuffy urban cousin into a long tradition of running roughshod over the lake, from midnight ice cream thefts to a scheme to lure rock and roll tour buses up the hill for open air concerts. Henri and the Savages go on a mission up a canyon in search of a mythical diving board once used by the since disappeared Diving Ranger of the sixties only to unlock the mystery of the lake's very existence. Along the way Henri builds relationships with the eclectic residents of the small lake town. Including the Flying Gibson's two brothers who build rope swings and Arlie who runs a strange radio station broadcasting from an antenna in the middle of the lake. Henri discovers herself and sheds her fears in one perfect summer.