Has this author ever done any research? Seriously. I do not think this guy understands that there are many bones within the human chest and one does not simply stab someone in the heart, especially the way such actions are presented in this book.
From what can be gathered about the protagonist, he has never killed anyone. A white-collar office worker in his late forties to early fifties, who has led a peaceful life, manages to take out five to seven combatants within the the breadth of the sample alone. No.
I won't even get into the poor GSP. Will not be purchasing.