This is a sad story. Those who had to leave their hometown because of the construction of a huge dam must have felt lonely, sad, and heartbreaking pain in their hearts. Even having to leave your hometown for just a few years makes you unhappy, it is countless times sad if your town is underwater and disappears forever.
The seed keeper woman, at the end of the story, seems to suffer from Alzheimer's disease, forgetting things in the past. That may be a way of happy ending.
The novel is so full of poetical sentences and metaphores that it was difficut to understand it well. However, gradually, toward the end of the story, I began to appreciate his style.
The write, Anthony Doerr is a Pulitzer Prize-winning author.
Has he visited the dam construction site in China to collect the material for the story?
It would be interesting to describe in a novel how people in Tokuyama felt when the Tokuyama Dam was constructed. They moved the cherry trees to the top bank of the dam from their village to appreciate the beauty of the cherry blossoms they enjoyed while the village was not underwater.