Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Painful to read

I don't expect great literature when I read a detective story, but it would be nice if the plot was at least remotely believable and the author had some facility with the English language. Unfortunately, neither is true here. I actually winced when reading portions of this book and finally found it too painful to continue. I am impressed with one thing: that an author of such mediocrity could get his work published.