How many people have been killed on "The Walking Dead" so far? I don't mean walkers, but living, talking, feeling human beings. I don't know the exact number, but I do know it's been enough for several characters to no longer feel much of anything when shooting someone in the chest or driving a knife through their temple.

Count Rick, Michonne, Carol, Abraham, Daryl, and several others in their ranks among those deep in the rabbit hole of death, moving closer and closer towards callousness. I don't mean to make them sound like horrible people -- they're not. But even if their discrimination surrounding who they murder (remember, they chose not to kill Jesus a few weeks ago when they very easily could have) gives them more compassion than The Hunters, all of them are still able to execute someone with that group's detached precision. If Rick had all of The Saviors bound at the wrists and on their knees, you could picture him nonchalantly slitting their throats one by one.

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Because of the high body count, however, we often forget that not everyone is like the more ruthless characters on "The Walking Dead", and I'm not just talking about the more pacifistic Alexandrians either. Sure, Morgan's refusal to kill (at least later in his life) has been addressed plenty, but as "Not Tomorrow Yet" reminds us, Glenn hasn't killed anyone either. And when he and several others from Alexandria infiltrate The Saviors' entrance bunker under cover of darkness, he knows the mass murder they're about to commit shouldn't be taken lightly.

On one hand, The Saviors -- judging from what little we know of them -- are monstrous. They've strong-armed the Hilltop Colony into giving up half of their supplies, unnecessarily killed several of the refuge's citizens, and nearly killed Daryl, Abraham and Sasha. But we've also only heard about most of these incidents, not seen them. And, if we're being fair, Daryl did steal their shit.

I don't think "The Walking Dead" is proposing that The Saviors are secretly not all that bad. I've read the comics and, like all of you, have noted the ominous nature of all the whispers surrounding them. And from what we saw during Daryl's encounters with them in the woods and on the road, they don't seem like people I'd want to hang out with.

But Glenn doesn't know that. And even if he does believe The Saviors are as awful as everyone says, he never sees one of them until he's holding a blade above the skull of a guard as they sleep. He goes through with the methodically barbaric act, but his gasping and slight tears hint that a small piece of his soul has left his body as a result. The weight is so unbearable, in fact, that Glenn -- truly decent person that he is -- kills Heath's target for him as well, sparing his friend from having to chip away at his own psyche. In a cruel twist of fate, both of them are forced to kill multiple Saviors just a few minutes later when the alarm gets triggered and all of the sentries wake up. Even though shooting at a horde of charging enemies through a door isn't as directly savage as stabbing them in their sleep, neither man will be the same when (and if) they leave the Saviors' camp.

Because of their hesitance, the invasion is equal parts espionage thriller and morality play -- thrilling whenever John Carpenter-esque music swells under Rick and the others covertly taking out an opponent, and unnerving whenever we see Glenn and Heath silently freaking out over what's happening around them. Director Kari Skogland takes the art of contrast even further by preceding the carnage with pure suburban bliss in Alexandria: Carol bakes beet and acorn cookies for everyone, then gets sweet on Tobin. Likewise, Denise and Tara awkwardly make cute with one another before the latter heads out on the mission.

At the same time though, there's an unease among the newcomers to the neighborhood. Tara loves Denise, but knows that she's about to go on an impossibly dangerous journey that could keep their romance from ever reaching its full potential. Also, Abraham coldly ends things with Rosita. And as happy as Carol seems settling back into the role of homemaker, there's always a pessimistic darkness creeping underneath, made all the more obvious from external signals such as her passing by Sam's makeshift grave,

"Not Tomorrow Yet" also contains more obvious foreshadowing of what lies ahead. There's the female voice over the loudspeaker at the end telling Rick and everyone else to stay where they are, indicating that the mission hasn't gone as smoothly as everyone thought. But I'm more interested in the Polaroids Glenn sees on the walls of the bunker. Could all of those dashed brains be the work of Lucille? I think so...