Second Skin
I started Second Skin mid point in the series apparently and really needed to read the previous books to understand what the heck was going on so I spent most of my time lost since I had no idea when I picked it up that it was a part of a series. Although I liked the story the characters didn't impress me but I'm still curious enough to want to start at the beginning to fill in some answers to the many questions I have about the book.