Nicola Yoon said "this book slipped quietly under my skin" and I'd have to say that really described how I felt about this book. I could feel the grief and loneliness that Marin, our protagonist, feels throughout this book. It felt kind of like a YA meditation on grief and loneliness. However, there's a part of the book that hits on a betrayal and I'm not quite sure I felt as strongly about the reveal to say it was a betrayal. For me, this event continued the feeling of sadness but I felt a bit of a disconnect with Marin and how she processed the reveal.  This book is also about family - both biological and chosen.  I read this in print and listened to it on audio and I think it works well both ways.