4.5 stars 
 What is it with authors making me feel emotions lately? I may have to lay on the floor and feel things for a few weeks. 
 One is about 16-year-old Grace and her conjoined twin, Tippi. I've never read a book on this particular subject matter before and so was intrigued to do so. I'm glad I did - I think this must be a difficult topic to write about but Crossan has researched it will and written it not only beautifully but with a level of grace and sensitivity that is quite admirable. 
 The book, to a large extent, is not about the direct problems associated with being a conjoined twin. In fact, Grace (and assumedly Tippi) doesn't really mind being conjoined in the most basic sense of it. This makes sense really - if you've spent your entire life with someone, physically attached to them, it's understandable for the thought of being without them to be upsetting. Change is a frightening thing, as is loss. 
 Something many people have commented on - and loved - is the writing format. The whole book is written in verse. 
 To be honest, this annoyed me at first. I got used to it but still think it was completely unnecessary and adds nothing to the book. I don't feel that it really is written as poems, it's written as a novel and then made to look like poems. I know a lot of people loved that it was written in verse but I personally don't understand why. 
 Other than that, I think the book is well written. Sarah Crossan has a way of writing that is simultaneously light and deep - meaningful, engaging. I loved the characters, I root for them, I feel sad when they're sad, frightened when they're frightened. Somehow, Sarah Crossan writes in the same way as many other YA writers but, only most of them, she does it really, really well. 
 The book has meaning and it emotionally involves the reader in a way that so many similar writers completely fail to do. 
 As much as I did like Apple and Rain, One is my favourite of Crossan's books so far. Also it has a pretty cover - I know, I'm shallow.