In this volume, we are beginning to understand the nature of the apocalypse. This epidemic is not something our group of survivors can outrun or protect themselves from. The fact that people who are dying without being bitten, means that everyone is already infected. This disease isn't something that's ever going to end or get better. This is now the new normal. 
 Even though the natural order of things has been abolished, some things never change. The differences between the individual survivors becomes more apparent. After the apocalypse, people can find their humanity and hope to create something better. On the other hand, some people are just as evil or insane as they were before the apocalypse. 
 When society crumbles it feels like humanity is the first thing to become distorted. This is evidenced in Rick. (view spoiler)[He shows a kindness by going back to re-kill Shane, even though he has every right to hate the man. Then, he shows a brutality when he nearly beats Andrew to death after it's discovered that he was the one who killed Hershel's girls. (hide spoiler)] It shows just how far everyone has gone away from their former selves. 
 I'm interested in where this will go next after that cliff hanger ending.