For the past two decades, Rocky has looked forward to her family's yearly escape to Cape Cod. Their beach-town rental has been the site of sweet memories, sunny days, great meals, and messes of all kinds: emotional, marital, and - thanks to the ancient plumbing - septic. This year's vacation, with Rocky sandwiched between her half-grown kids and aging parents, promises to be just as delightful. And then a chain of events sends Rocky into the past, reliving both the tenderness and sorrow of long-ago summers. And when Rocky comes face to face with her family's history and future, she is forced to accept that she can no longer hide her secrets from the people she loves.