The Walking Dead, walking dead season 5It's been pretty clear over the past four seasons of "The Walking Dead" that the titular zombies are merely sideline characters in their own apocalypse, as the human stars of the show – and the crazy, high stakes drama that they manufacture – have been the main focus of the series since its inception. So it was a pleasant surprise to see a huge horde of the undead play such a key role in Sunday's fifth season premiere, as zombies overtook an explosion-rattled Terminus to finish the job that Carol (Melissa McBride) started.

Yes, we finally learn the truth about Terminus – yep, they're definitely cannibals – only to see the settlement destroyed by episode's end, as Rick (Andrew Lincoln) makes good on his vow at the close of season four to prove that their captors were "screwing with the wrong people." But it's Carol who sets that plot in motion, thanks to an ingenious plan to infiltrate the settlement via the aforementioned group of walkers, and a pair of well-placed gunshots that bust open a propane tank and then light it on fire, starting season five with a literal bang.

But we're getting ahead of ourselves.

The episode begins with a flashback (denoted by a "Then" title card) to brothers Gareth (Andrew J. West) and Alex (Tate Ellington, who was killed by Rick in the season four finale) hunched in a train car not unlike the one Rick's group winds up in, listening to their people being tortured. Flash forward to "Now," with Rick's gang readying to duke it out with the Terminites using makeshift weapons, only to wind up with Rick, Glenn (Steven Yeun), Bob (Lawrence Gilliard Jr.), and Daryl (Norman Reedus) gagged and bound and hunched over a trough, waiting for their throats to be slit.

The foursome survive the encounter, thanks to Carol's aforementioned firebomb, which sets Gareth in a tizzy and leaves Rick (who'd snagged a sharp scrap of wood from the train car) to take out the guys about to kill them. Rick's manifestation into a calculated killing machine -- which began in the season four finale when he chomped on a guy's throat -- continues in this episode, as he encourages Bob to leave the dead Terminus goons to turn into zombies, then instructs the others to kill any and all Terminites they see. Later, when the group escapes the burning, zombie-riddled settlement, Rick is determined to double back, telling the others, "It's not over until they're all dead." Thankfully, he abandons that plan, but not before the rest of the group exchange nervous glances, eyebrows raised. That insatiable bloodlust will no doubt come back to haunt the gang in future episodes.

Speaking of bloodlust, Carol has once again proven herself to be a major badass thanks to her quick thinking and willingness to sic walkers on the living, as she does with Mary (Denise Crosby), last seen serving up grilled chunks of mystery meat (surprise: it was human flesh!) to Rick and co. in the season four finale. As she sneaks into Terminus (thanks to some slathered-on zombie guts, a callback to one of the grosser moments of season one), Carol stumbles upon the eerie message "Never again, never trust, we first, always," and learns its origins from Mary. Terminus did start out as a sanctuary, she explains, but was taken over by people who raped and killed members of their group, leading them to adopt the motto, "You're the butcher, or you're the cattle."

Unfortunately for Mary and the rest of Terminus, they wind up on the cattle side of that equation, as Carol casually unleashes the undead on them and leaves the settlement in disarray. It remains to be seen whether we'll hear from any of the Terminites again, though considering Gareth's fate was left on an ambiguous note, I'm betting that he'll make at least one additional appearance this season.

As for where all this leaves Rick's gang, that, too, is unclear, since they're once again on the move. The plan will no doubt be to continue to Washington, D.C., where Eugene (Josh McDermitt) has claimed that a cure for the zombie plague is waiting, but that journey will certainly be a long, strenuous one. Based on the previews for next week, we're about to meet Gabriel Stokes, a.k.a. The Preacher (played by "The Wire" alum Seth Gilliam), so Rick's group won't be left alone for long.

Other thoughts:

- You may have noticed that your DVR was set until 10:01 p.m., and that's because "TWD" saved its biggest bomshell for the episode's extra seconds: Morgan (Lennie James) is still alive! (Did anyone else shriek with delight, or was that just me?) It seems he's gotten over some of the issues he was working through way back in season three – he's suited up in protective gear and wearing a mask, he's actually outside – but is he going to join up with the group? He's tailing them, but how far behind is he? Judging by how spaced out his two previous appearances were (the first was in the pilot, for those who don't remember), it may be a while before we get those answers.

- "The chick with the sword and the kid in the hat" = an oversimplified, yet still perfect, description of Michonne (Danai Gurira) and Carl (Chandler Riggs).

- The Terminus resident that Tyreese (Chad L. Coleman) holds captive gets in some good lines, describing his fellow Terminites as "Just a--holes I stay alive with." He also notes that "Horrible s-t stacks up day after day" during the zombie apocalypse, which could be the tagline for "TWD."

- Speaking of that guy, he helps Tyreese get over his "I can't kill people/zombies anymore because I was an accomplice in the murder of a child" syndrome, which sprung from Carol taking out Lizzie last season after the little psychopath killed her own sister. Threatening to strangle baby Judith is just too cruel, even for a cannibal.

- ICYMI: The body on the slab that the Terminites are fussing over when Rick and co. are awaiting slit throats is Alex. Apparently, you don't waste perfectly good food in Terminus, even if that food is your brother. I guess the family that eats together stays together, huh?

- This week's award for Best Zombie in a Walking Dead Episode goes to Burning Zombie No. 1, who walks over to a terrified Terminite, knocks him over, and begins feasting on his face, all while aflame. Disgustingly awesome.

- Eugene describes the zombie cure as coming from his research into fighting disease with other diseases, a solution that leaves the others (justifiably) skeptical. "It does sound pretty badass," he says smugly of his plan. Sure, buddy.

- Daryl's tearful reunion with Carol in the woods outside Terminus – sprinting to her and throwing his arms around her in silent joy – may be one of the emotional highlights of the entire series.

- Co-creator and executive producer Robert Kirkman has promised plenty of bloodshed this season, and yet, aside from some random Terminites, no major characters were killed off during this episode. While I'm happy to see that Rick and co. were spared from dealing with yet another devastating loss, I know that this good luck won't last long – and probably not even through next week. I'll see you then.

Photo credit: Gene Page/AMC