I don't want to say too much about the lessons here since it might veer a bit too close to spoiler territory, but there's a really nice build up in the way that it flits through timelines. There's a weaving of a picture of a woman coming to grips with the question of nature or nurture, looking for a way to gain closure in something she has no control over, the migratory path of a bird. A heavy read but well worth it in what you get from it.