I'm a well read grad student who's bluntly honest about all things, although I try to be most honest about myself.
This one delves into the past: both Castle's and the case's past, all the while bookended by the present. It's another fast and furious issue, with less violence, but the violence that is there questions when a kill during war is righteous. Defending yourself, yes, but killing innocents because it's easier?
Frank says no. Others disagree. It's all telling about who he is and how he treats people and makes sense, even given what he becomes. His policy is the same as the Punisher as it was when he was a soldier: killing those who terrorize and take advance of others, who kill and murder and rape, is fine by him. Killing innocents is not.
The art matches the story perfectly, as well. Love, love, love this run!