Carol hasn't been the same since Lori's death and being trapped in the tombs. In fact if you recall she was operating on zombie's to practice a c-section for Judith's birth - so she had already started that trip around the bend for a while.
There's a big difference between using a zombie as a cadaver for an impending surgery and killing two alive people and burning their bodies.
Was what Carol did really that "dark"? She was trying to prevent a plague. She failed, but stopping it early was a good idea. She should've talked to others about it, but then she has seen how the group will talk in circles about difficult choices (recall season 2, and the unending discussion about whether to kill their prisoner), so doing something unilaterally probably seemed to be the smarter choice when time was short. At any rate, I don't think there's a necessarily a "trigger" for Carol's behavior, just a slow and steady progression towards cold, logical decision-making.
She did tell Andrea to sleep with the Governor and kill him while he slept. Andrea didn't and wound up dead at the Governor's hands. I'm sure that affected her enough fror her to do what she did this season.
That's why the people were contained in A-Block/Death Row. To prevent the spread of the illness. And yes what she did was dark considering she killed two living people not posing a meaningful threat. What she did with the bodies is another discussion, but she still killed to living/non-walker people who were contained. That's pretty damn dark. Along another line... It's a common TV/movie trope to do this but covering your mouth/nose with a mask or cloth doesn't do anything to protect the wearer. If you can breathe through it you can breathe in germs/viruses/bacteria given that those things are aerosolized in air molecules which your mask is porous too. Wearing mask protects OTHERS from YOUR germs, coughs, spittle because the mask can contain those things (aerosolized germs and such being much more contained just off the mouth than in open air.) So, really, everyone wearing a covering in the episode isn't doing themselves too much good. No harm, sure, (and it's is SOME protection from flying spittle/blood) but it's not a 100% defense from germs and viruses in the air. Is it me or did this episode step down the aggressiveness of the virus? In the first episode Patrick goes from "not feeling well" to cough up blood and dying within a few hours. Right now it seems everyone is sort of managing the virus a bit better.
We saw the same progression with Shane and that didn't end well. Albiet Shane was a little more around the bend by the end than Carol is currently. I wonder if she's headed down the path of, "logical decision-making," to outright paranoia as we saw with him?
OK, I guess since she admitted that she killed them, they must have still been alive at the time. At the end of the previous episode, it wasn't clear to me whether Karen and David were already dead, or had been killed. So, yeah, killing the living is generally a dark deed. What would the old Rick, the Ricktator, have done before turning soft? Would he have preemptively killed Karen and David?
Rick didn't preemptively kill any innocent people when he was around the bend, but he left plenty to die when he could have helped them because he didn't want to risk the group's safety, which is almost as bad. It's the reason I'm not too interested in this Carol plot line, it feels like a retread of Rick from last season, minus the dose of crazy.
Is he always like that? Sometimes I really wonder how they choose who gets invited here. I'd think whoever produces the show would think that a guy who rambles on in mumbles while possibly on something wouldn't be high on the list. By the end of the show they were all pretty much ignoring him (not that he seemed to notice). As for the episode, quite liked it. Carol was the solid focus here, and her journey to its end (and possibly her end) will be fun to watch. Rick is back doing a little police work, and Tyrese gets his ape-shit moment much as his comic counterpart got. I wonder how they'll be explaining the mega-herd though and if it will have lasting repercussions on the show. Obviously this herd has caused by many of the local ones merging (hinted as far back as the season three opener), which seems to be zombie behaviour dictated as much by simple physics as by anything else. But if that's the case, does that mean that the rest of the local area is relatively zombie-free? What happens when the mega-herd moves on? Will the show get boring again without free-range meat to carve up? Mark
Carol you need to go bye bye now am sick of her, shes gone way over the deep side of the looney bin. So many of the characters have loss their basic humanity I find it hard to relate to them or even care about them and season 4 overall feels a little meh at the moment.
There has always been a dialogue in the show between characters who think the only way to survive is to do whatever it takes and ignore any past rules of society, and characters who think they need to keep the rules of civilization unchanged in order to remain human. This goes back all the way to Shane.
^Because the conversations are different. Will Carol go down the same route as Shane? Impossible. She has different motivations and goals than Shane did. So we watch to see how things will be different.
Or does it matter at all which side of the argument you are on? Dale was definitely the other side of the argument and he ended up just as dead.