Although this books sucks and the movie is so much better, it still covers everything the movie does.
Somerset is the most important character. He has a lot in common with the ideas of John Doe. They both are sick of society. John Doe just decides to become a killer though.
The religious aspects of the Seven Deadly Sins are HUGE in this book. They ARE the book. The big issue is this: Are we guilty as a society for accepting these sins as ok or committing them ourselves? If we are guilty, what punishment do we deserve?
John Doe is a sick bastard, but besides the sick killing….do you think he has any good points? Is his killing justified?'
The relationship between Mills, Somerset, and John Doe is another huge part of this book.
Mills is the Naïve cop who think he is going to fight crime and evil by effort.
Somerset is the burnt out cop whose understanding of violence and crime wears on him and makes him want to quit.
John Doe is a creation of a man. Whoever John Doe was in life before this…the name and being of John Doe is a judgement on society.
Somerset makes a comment to Mills earlier about how his job has no victories. That all they do is pick up the pieces…collect the evidence. Mills argues with him and says they are following the law and stopping crimes. At the end though, when Somerset tries to stop the crime, he fails and ends up just picking up the pieces at the end.
Also, Somerset knows throughout the whole book that Mills is not capable of handling the job and the city….and it is proven at then end when he lets John Doe win and shoots him in the head.