Great format for commutes cause the mails break up the story into short parts. Here and there the wording feels a little forced cause the mails have to do the job of telling the whole story, but overall the concept works well. If you remember all the side characters - this novella won't explain again from scratch who everyone is. And you'll have a hard time enjoying this book if you're (understandably) over Harry Potter references; there are a LOT of them... Still had me close to tears a couple of times (in a good way), including at the end :)