The “Walking Dead’s” long, slow, at times frustrating, at times thrilling amble to Terminus finally came to an end on Sunday, in what occasionally felt like an assortment of summer movie ads interrupted by a TV program. Such is the enormous popularity of AMC’s zombie juggernaut, which — its missteps and detours notwithstanding — ended the season on another nail-biting note, setting up a tense scenario that should keep fans just as ravenous as always for the next flight of episodes — and movie marketers, not incidentally, just as keen on accessing all those eyeballs.

Admittedly, with the benefit of hindsight, new showrunner Scott M. Gimple — the program’s third in four years — was dealt a rather challenging hand. The breakup of the prison sent the key personalities scattering in various directions, producing what felt like a “Lost” dynamic, focusing on individual or pairs of characters from week to week, in what couldn’t help but become a trifle uneven.

Rick’s near-silent attempt to stay alive in a house filled with marauders, or the recent homage to “Of Mice and Men?” Outstanding. Michonne’s softening exterior, and warming toward Carl? A nifty wrinkle. Daryl (Norman Reedus) and Beth (Emily Kinney) exploring the prospect of playing house? Not so much.

Clearly, though, it was all building toward something, and Sunday’s hour (and SPOILERS are ahead) partially redeemed that wait — in a fast-paced episode that featured crazy violence; disgorged more back story regarding the mysterious swordswoman Michonne (Danai Gurira); further zeroed in on central character Rick (Andrew Lincoln) and his battle to maintain a semblance of humanity; delved into the hardening of Rick’s son Carl (Chandler Riggs); and finally, reassembled much of the core cast, albeit leaving their fate dangling.

OK, so Terminus might not be the sanctuary those billboards promised. Hey, it’s a cruel, sadistic, post-apocalyptic world, but at least they have each other.

Shrewdly, the producers brought back Scott Wilson’s fatherly Hershel — one of the more painful casualties on a long list of them — to highlight Rick’s darkened turn, and the toll the struggle for survival has exacted upon him. If Hershel was the equivalent of the angel on his shoulder, the closing moments made clear it’s the badass Rick who’s now in charge — and that the guy who once talked about not killing the living is way, way back in the rear-view mirror.

In that respect, the journey to Terminus ultimately led to one conclusion: Crystallizing that the real threat in this brave new world isn’t the zombies, but what people are capable of doing when law and civility breaks down.

It’s human nature, in other words, that creates both the hunger for security and makes it so elusive. And it’s those qualities that give “The Walking Dead” no shortage of meaty roads to follow, even in those rare moments when the show appears to be stumbling toward a dead-end.