Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Excellent thriller!

One of the best thrillers I have read. It's characters are complex, the plot is deep and explores every angle and the dialouge is sharp. I had a good idea who the killer was halfway through and then had to totally do a 180 and change my mind near the end. I ended up getting it right but was still not 100% sure. I absolutely love books like this, that keep you guessing until the end and books that you just can't put down.It is extremely hard to believe that this is the author's first book. He writes with the confidence of a seasoned author and makes no mistakes in this brilliant first outing.I highly recommend this book to anyone who likes their crime/mystery/suspense books fast paced, bloody, and well written.