Instruct: Classify Amazon reviews into positive or negative sentiment
Query: The most gruesome book ever!

Chromosome 6 was the first book I read by this author. Then I saw Toxin. Intrigued by the E. Coli virus, I picked this book.I was completely hooked from the start, even though some parts were rather unrealistic.But Toxin is a very, very depressing book. My guess is that Dr Cook worte it during a depressing period in his life. It shows the dark side of life, where profits are everything.One question remains in my mind: How true is it? Would the esteemed author care to let me know?A last warning: If you have eaten a burger within the past week, do *NOT* touch this book...