Really enjoyed this book. This is quite a new genre for me as I usually read paranormal rather than sci-fi, so this was a bit of a change for me and I wasn't sure how I would like it - but gotta say I loved it and am currently looking for more like this to read as its opened up a whole new lot of books for me to read!
On the down side, there were some annoying bits to the book - it got a little slow in the middle and I felt it dragged a little where they were travelling. And also the way Chaz was constantly too scared of asking questions or seemed to be quite dense at times to miss things that were obvious, but this did need to be done to an extent so as not to reveal everything all in one go.
Overall I really liked the story line though and the characters were great - I loved Ren's character too and hope to see more of his story in future books and also some of the others like Philip etc will hopefully feature more in the future.
The start was pretty fast-paced and strong. I liked the mystery around Sully unfolding and it was good that it wasn't revealed all in one go, so we discovered things through the whole story. The ending was quite exciting and fast-paced, solving enough of the mystery to come to a reasonable end to the story, but leaving quite a big cliff-hanger to leave me eagerly looking forward to the next in the series.
I would definitely recommend this book to friends, even if they haven't read this genre before.