Instruct: Classify Amazon reviews into positive or negative sentiment
Query: So Sad

I only mildly enjoyed book 1, but I saw potential, so I went ahead and purchased books 2 & 3. They were by far much better books and I was excited to read the 4th. Unfortunately, it was a very sorry addition to the series. None of the characters do any growing and the only real plot development is the addition of werewolves into the mix, which does nothing to improve the story. It just bogs down an already complicated story line started in the first three books. For some reason we leave all of the interesting side characters behind for these flat underdeveloped weres. I'm sorry but it turned Rachel into a poorman's Anita Blake. Hopefully, book 5 will get back on track, but I'm waiting for the reviews before purchasing.