Ruth and Peter have been married more than fifty years. He is the headmaster of the Derry School, a boys’ boarding school in Maine; she has spent the four decades of her husband's tenure helping out wherever she is needed. But Peter’s retirement is approaching, and Ruth wonders what will become of them when it finally arrives. How will they survive separated from the school into which they have poured everything, including their savings?
 
As the story takes us back through the years, revealing the explosive spark and joy that brought Ruth and Peter together in their youth, The Last First Day becomes a deeply felt portrait of a woman from a generation that quietly put individual dreams aside for the good of the partnership, and of the ongoing gift of loving and being loved in return.