This was a original and moving novel about reading; more specifically, how no two people will read a book the same way. It's tightly structured, taking us chapter by chapter through the creation of a book -- the author's inspiration and creation, the agent who recommends publication, the actor who narrates the audiobook, and all the readers who pick it up. Amusingly, not all of them actually read it; one artist resents its popularity and the fact that it was her mother who gave it to her; nonetheless, it becomes a part of her masterpiece sculpture.
There are other elements besides the book that link the stories together, such as a traveling nurse who knows several of the readers, an essay written by one that inspires another, the image of slipping under water. These are, I think, ultimately unnecessary, because the crux of the novel is how each character encounters the book and is affected by it. For one, it inspires hope, for another, it forces a change of perspective, for a third it represents a life-long achievement. One character finds healing and another wrestles with a long-buried trauma. All of them come out of their encounter on a new path. I can't think of a better way of demonstrating the power of a good book.