The Garretts take their first and last family vacation in the summer of 1959. They hardly ever venture beyond Baltimore, but in some ways they have never been farther apart. Mercy has trouble resisting the siren call of her aspirations to be a painter, which means less time keeping house for her husband, Robin. Their teenage daughters, steady Alice and boy-crazy Lily, could not have less in common. Their youngest, David, is already intent on escaping his family's orbit, for reasons none of them understand. Yet, as these lives advance across decades, the Garretts' influences on one another ripple ineffably but unmistakably through each generation.