A review of tonight's "The Walking Dead" coming up just as soon as I don't plan on much typing the next few days...

Last week, I lamented that the time jump between seasons had made it more difficult to properly develop the new prison characters, and to advance the arcs for the characters we already know. "Isolation" did a much better job at both — even if some of that was the result of consigning virtually every newcomer besides Bob (plus a few familiar faces in Glenn, Hershel and Sasha) to the isolation ward where they will either get antibiotics or cough themselves to death.

There were lots of strong character beats, big and small, for people we know fairly well like Carol, people we vaguely know like Tyreese, and people we've just met like Bob. Bob staying to help Tyreese dig graves for Karen and David, for instance, may not seem like much, but compared to the utter lack of development given previously to the likes of T-Dog or Oscar, it was practically a Shakespearean soliloquy. Assuming this isn't a signal that Bob isn't long for the world ("TWD" background characters usually only do or say memorable things right before they die), it's a welcome sign that the current creative team realizes they have to devote more time to the newbies or we'll only ever care about the ones we already know.

Even better was Tyreese's explosion on Daryl and Rick about Karen and David's murder. Until now, he's seemed a steady, dependable guy and not much more, but the level of rage Chad L. Coleman displayed in that scene was terrifying, and I was just watching him on a screen, rather than being shoved against a wall by him. (Andrew Lincoln's no slouch, but Angry Rick in that scene paled in comparison to Angry Tyreese.) His fury at the murder of his friends, and at Rick's lackadaisical approach to finding their killer(*), was understandable, and raw, and the most memorable thing to happen this season that didn't involve zombies falling through a ceiling. It was so good, in fact, that I was frustrated when it seemed like Tyreese was going to die during the later zombie attack, not only because he had finally turned into a compelling character beyond residual "The Wire" love, but because it seemed a stupid way to die. Tyreese was fixated on saving his sister and getting justice for his dead girlfriend; why would he suddenly decide to give up like that? That he somehow survived that swarm with nothing but his hammer and his strong right arm seems wildly implausible (and maybe we'll find out next week that he got bitten), but I'd have been very annoyed if he had died just then.(**)

(*) A lack of urgency by the characters has been a periodic "TWD" problem, but at least in this case Tyreese called Rick out on it, even if Rick's defense wasn't the best. Even if you're more focused on the contagion, you need to make sure that people aren't being killed before it's too late to save them, you know? He didn't seem to figure out that it was Carol until he revisited the crime scene, so it's not like he was stalling to protect a friend.

(**) Also, it would have continued the show's unfortunate pattern of having room for only one black male character at a time. Enter Oscar, exit T-Dog. Enter Tyreese, exit Oscar. Enter Bob... and for now they are co-existing. 

That Carol was revealed as the killer plays into her evolution as perhaps the coldest, hardest character left in the group. The Carol we met doing laundry in the quarry is long gone. The abusive husband who made her a timid mouse is dead. Her daughter is dead. She's had to find a new reason to go on, and that reason is protecting her friends and staying alive, no matter the cost. Melissa McBride has gone from an afterthought in a big ensemble to one of the show's more valuable players, and I look forward to the repercussions (or lack thereof) of her confession, especially when/if Tyreese gets back with the meds.

Beyond that, the plague has been an interesting new direction for the show. The first season was about surviving zombies. The second season featured a lot of internal tension between Rick, Shane, Lori and Hershel. Season 3 steered even more into human-on-human conflict with the introduction of the Governor. This threat is something else. As Glenn notes, there's no enemy to fight here, and little that most of them can do without medical training or supplies. They are largely helpless, and that situation is revealing new sides to the characters, whether it's Carol turning killer or Beth (who has finally started to come into focus this season) compartmentalizing just so she can tend to her duties with L'il Ass-Kicker.

"Isolation" was also a terrific-looking episode, thanks to the work of veteran director Dan Sackheim, and even if not all the story beats make sense (why are the zombies not attacking the fence en masse anymore?), this was definitely the most engaged I've felt of the three hours so far this fall.

What did everybody else think?

Alan Sepinwall may be reached at sepinwall@hitfix.com