I received a copy of this book for free from Netgalley, in exchange for an honest review. Thank you also to the publisher, HarperCollins. This review is also posted on my blog, Rinn Reads.With so many positive reviews, blog tours and general excitement around the book blogging community over this book, I felt I should give it a try. On first read of the blurb, I was reminded of Stephanie Meyer's The Host, a book full of lacklustre characters, in which not much happens. Which makes What's Left Of Me its complete and utter opposite - the society in which it is based slowly appears more and more sinister, and I actually cared for the characters within a matter of pages.It is explained throughout the book that every person is born with two souls, one dominant and one recessive. The people of this world - which is ours, but I'm not sure if it's a future or parallel universe - believe that one of the souls will naturally disappear, which is known as 'settling'. Now, with this being a dystopian novel, you know it can't be that simple. Children are meant to settle around about five years old, with ten being the cut off point. However, some do not - and these 'hybrids' are seen as dangerous, and shipped off to be 'cared for', and never seen again.I do feel that there could have been a little more development with the world building. Is this our Earth, in the future? If it is, when did people start being born with two souls? Is it a parallel universe? Why is there only really talk of the Americas? As well as this, it seemed very odd that all these families would be effectively losing a child - as each soul has their own name, and is treated as a separate person - but very few seem really bothered by it. Perhaps it is just one of those things that society just accepts at face value, because they can't be explained. As well as this, the use of 'we' and 'our' instead of 'I' and 'my' etc, certainly took some getting used to; at times the writing felt a little clunky for it. However, I believe that Kat Zhang made the right move in only having Eva narrate the story, otherwise it would have gotten incredibly confusing.What starts off as seemingly a pretty normal society slowly darkens, until the reader realises just how little the people of this world know. Part of the book made me feel almost claustrophobic - in a good way - because I could completely imagine the situation the characters were in. Zhang's writing flows very smoothly. And thank goodness for the lack of love triangle!I rushed through the last twenty percent or so of the book - it was a thrilling and very tense ending, though some events could have perhaps been shown, rather than told. It also set up what I believe could be a possible plot for the second book - which I will definitely be looking out for!Overall, I really enjoyed this one, and it took a couple of turns that I did not expect, and I few I managed to guess. Definitely worth a read if you're a fan of the YA Dystopia genre.