This was a good read, an interesting world, and I liked our main characters, especially Ward. He reminds me a little of Tavi in the Codex Alera series, where although he isn't all brawn and lots of special powers (yet anyway), he still manages to be smart and kind, and even save the day despite pretty bad odds!
Celia is hard to warm up to, but still an interesting character and although her distrust was frustrating at times, it was probably very realistic for the situation she was in and given her background.
The relationship between them grew quite realistically throughout the book - it was more friendship and learning to trust one another/rely on another person more than anything romantic. Although there are hints at something more, nothing happens between them except for a couple of kisses in this book but you can see why this would be with the circumstances and this made it more realistic. I did find it frustrating that neither of them shared key things with the other though, which would have helped them work out what was going on a lot easier - I understand the distrust but I am sure some of the things wouldn't have mattered if they shared them and would have helped them out!
Quite a lot happens in the book and all the pieces start coming together as you go along to create the big ending. Although the main part of the story is wrapped up at the end and there is not really a major cliffhanger as such, we are still left with some loose ends which go through into the next book and set the scene for the next in the series.
We also hear from the villain's POV a few times, which adds a snippet here and there to our understanding of how things are unfolding, but without spending a long time on these pieces (which I prefer) - many books add these additional POV and you kind of just want to skim through them as they are taking away from the main character interaction, so these were quite nicely done.
I shelved the book as "young adult-mature", as despite there not being any adult-only content, the characters were definitely not silly teens. I think they were both supposed to be around 20 years old and could easily have been quite a bit older.
I found the book frustrating at times, as every so often there was a lot of detail being described about things (such as the architecture of the buildings and such like) that seemed irrelevant and I almost skimmed some of those pieces, and as I said above, the building distrust between the characters, especially towards the last part was kind of irritating, but I guess needed for the story to continue as it did.
Overall, while I really enjoyed the read, there was just something missing for me that stopped me from being really gripped by the story and I can't quite work out what. But I am still eager to see how things go between the two and if Ward is able to develop any more impressive powers in the future, so I will be reading the next in the series at some point, but I might wait until we hear when the third book will be out as there was a two year gap between the first and the second in this series!