This is all going to be a bit spoilery, but I'll try to keep it vague.
Sever is Lauren DeStefano's final installment of the Chemical Garden Trilogy. I have been wanting to know what will happen to Rhine for what feels like ages. I definitely expected what happened to Vaughn, thought didn't expect how it happened. I pretty much figured out what the "Chemical Garden" was after I read Fever. I can't believe what happened to Linden. What happened to Gabriel was a big surprise. I expected Rhine to spend half the book looking for him and the other half looking for her brother. I have to say, I did not at all expect the twist with Rowan and Vaughn. Everything was Vaughn! Ahh!
I really enjoyed how the characters grew over the three books. Rhine matured, wanting more than just to find her brother, but that remained her main motivation. Linden learned so much. Gabriel did too. Cecily was wonderful. We really get a feeling of closure by the end, we know what happens to all the crazy people we encounter. I also really liked that the "love triangle" wasn't really a triangle.. it was more like a hexagon! I did like that it was never about Linden versus Gabriel. I also liked that each had their own time to really get to know Rhine and Rhine to know them. It was a wonderfully satisfying conclusion. I'm looking forward to more work by Lauren DeStefano, now that The Chemical Garden has been harvested.