This was the season that “The Walking Dead” finally lived up to its promise. It’s bloody, gory, terrifying promise.

This season the Grimes clan settled down in the West Georgia Correctional Facility and ran afoul of the nearby survivor community of Woodbury and its homicidal leader, the Governor. The show became about two separate groups of survivors trying to build new lives for themselves in a world that has driven them all insane to one extent or another. It was within that framework that this show actually became about more than just zombies.

The first season was really just a six-episode experiment. The second season was a full-blown affair, and it delivered some great moments, but it also suffered from a lack of focus, and spent a lot of time with characters going over the same rhetorical ground.

Season three, though, has seen this show become everything fans wanted it to be, and it’s somewhat surprising that the fulfillment of that promise has been concurrent with the show become one of the top features on television. The story about the survivors of a zombie apocalypse has been vastly more dramatic, taut, dark and gory than it was in the first two seasons. It’s not the typical ratings-hog material, but that’s exactly what it’s become for AMC.

The story changed, from one about survivors running, to one about survivors building a home, and the trials and deprivations they have to go through to build that home,all online movies. It also has been about, of course, the violent, murderous impulses that lie deep in man’s psyche that are unleashed once the bonds of civilization are broken.

It’s about two homes, really: the Grimes clan and their attempt to make the West Georgia Correctional Facility safe, and Woodbury. The former seems a hellhole and the latter a relative utopia. As the season progresses, it becomes clearer and clearer that the prison is indeed a hellhole, but Woodbury is not the utopia it seems.

Each episode has been almost a miniature horror movie, and there have been plenty of gut wrenching moments: the Governor’s first assault on the prison, Lori’s awful death, Michonne and the Governor’s fight in his apartment, Hershel’s bite and near-death. Indeed, one of the scariest moments of the whole season came when Lori was trying to revive Hershel after he stopped breathing. As she was giving him mouth-to-mouth, he came to, gasping and lunging and grabbing her. Nobody knew for a second whether he was alive, or a zombie.

We’ve lived with these characters to see that most of them have changed dramatically. Hershel, Carl, Daryl, Carol, Glenn, Maggie; they’ve all changed. But nobody’s had it harder than Rick; the burden of leadership, the loss of his (estranged) wife, having to kill his best friend. This season Officer Friendly broke under the strain, and until the final shot on Sunday’s finale, it wasn’t clear if he was all the way back.

The saddest transformation was that of Morgan, who we saw only in the pilot episode, and then again this season in “Clear,” one of the show’s best hours. Morgan has been driven insane by the consequences of the choice he didn’t make: shooting his zombie wife, who later shows up and attacks his son Duane. He’s living along with his demons – and a town’s worth of zombies, and a brigade’s worth of weapons.

None of the characters have been quite as interesting as Daryl Dixon, played by Norman Reedus. Daryl – who incidentally didn’t even exist in the comic books that are this series source material – was a mini-Merle at the show’s outset. Over the three seasons, his character’s grown both as a member of the group, second only to Rick in leadership, and as a person. When the backwoods loner with a crossbow picked up a bottle and started feeding little baby Judith this season, you could almost hear women across America swooning. Daryl’s become so popular, in fact, he is probably the one character on the show, even more so than Rick, that is unkillable. With big hit shows, somebody from the cast usually becomes a breakout star, and the one poised for that role right now seems to be Reedus.

Watching all these characters grow and change is what keeps the show interesting; boring, flat characters getting eaten by zombies every week would get boring. The other big change this season, though, has been the introduction of a danger beyond zombies: humans. For the utopia at Woodbury is run by a madman, the Governor. As portrayed excellently by David Morrissey, the Governor may well be the darkest, most inhumane, malevolent villain in TV history. J.R. Ewing didn’t keep severed heads in fish tanks in his mancave, that’s for sure.

The success of the show has to be a surprise. Fantasy-type shows don’t have much history on TV. “The Twilight Zone,” now regarded as a classic, ran for five seasons, and was constantly struggling with ratings and bewildered sponsors. “Star Trek” was famously canceled in its third season. “,movie and tv t shirts;Battlestar Galatica,” the campy ‘70s series, lasted barely one season; “Battlestar Galatica,” the gritty Aughts remake, ran for four credible seasons. “Lost” was popular, but as then ending made clear to disappointed fans, it was more gimmick than story.

“The Walking Dead,” though, has gotten progressively more popular, and better written and produced. Those are not unrelated strands. It’s the top rated cable show, and would be a top-10 show on broadcast television. That isn’t where you’d expect a zombie show to be. Top rated shows, for better or worse, are safe, comforting, relaxing. It’s hard to recall a show this violent, bloody, and dark ever being so popular.

The impulse is to extrapolate that success out into some kind of commentary on the national mood. These are rough times, and apocalyptic tales are always more popular when times are grim. It’s always possible, though, that people are just drawn to good shows, and that The Walking Dead proved this year that it is indeed a good show, not just a bloodfest.

It’s a bloodfest, too, mind you. Just a really, really good one.