This was a sweet, interesting take on some familiar paranormal elements. My favorite thing about it was that the fact it was familiar didn't feel repetitive and like a rehashing of books I've read before, but that it felt like a nice, comfortable visit with an old friend.
Simon was a delightful character, and I loved that he never let himself fall into the claimed-mate damsel-in-distress role. He had confidence in his own abilities, and didn't let Gray get away with his attempts at being an alpha caveman.
I also loved, though, that Gray didn't really try very often to be an alpha caveman. He wanted his family and Simon to be safe, but he recognized that Simon was his own person and didn't try to boss him around. And that the "mate" thing was something that they both still had to choose.
I'm glad book 2 is already out, though, since I still have a lot of questions I'd like answered.