The Batman of Arkham

Arkham: un Elseworlds de Batman. From the diary of Dr. Bruce Wayne, Arkham Asylum, 1900 Humans have a natural revulsion toward murder. It's a basic thing in man, he carries it in his blood, it's part of being a human being. But some men kill for pleasure. What is the line that these beings cross, that transforms them from humans into murderers? I have dedicated my life to trying to answer this question.