Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Mystery Must

The Moonstone by Wilkie Collins is a 'must read' for anyone who has ever enjoyed a mystery novel. Not only is it a very enjoyable and well written work but it's the first of the genre. It is the forerunner of Sherlock Holmes, Agatha Christie's great works and everything novel about the mystery novel. Buy it. Read it.