Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Unclear to me what the theme of this book is

Specimen Days consists of three stories, with in each of them a woman, a man and a boy. The first story is located in New York at the time of the Industrial Revolution, when a young boy has to take the place of his older brother when the latter dies during an accident with the machine that he operates. In order to safe the girlfriend of his deceased brother he mutilates himself... The second stories plays in the present time and portays the life of a police woman who tries to prevent random violence from people with mental problems and who is more or less overwhelmed when all of a sudden children start committing suicide bombings... The third story is located in the future, when Earth has made contact with another civilization and a Nadian and a humanoid flee from theme park New York to go to Denver. It is unclear to me what the common theme of the book is and the stories were not overly interesting.