Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not invisible, simply nothing there

A droopy lead character: like a Debbie Downer, who always finds the down side. There is no ending, just a last page, and you say, "that's it?" And why this doctor doesn't realize he is suffering from depression, and write himself a prescription for prozac? But here's my prescription for the author: don't write books anymore, and all will be well.