a world which has been destroyed by its own sins, a wasteland in which values are minimal. The killer, having nothing but contempt for this world, sees it as his mission to expose the faults and show everyone what they have become. It is a fascinating twist that when the killers motives become clearer, Somerset with his greater understanding actually feels some degree of empathy with him. This is lost on Mills though, whose level of clarity never reaches the same point.
the fight against evil is destined to be a Pyrrhic victory. But regardless the only thing we can do is fight on whatever the cost. We have no other choice.