Season 1, Episode 3, “The Dog”

This post contains spoilers for Sunday’s episode of “Fear the Walking Dead.”

You can’t reason with a zombie.

If that sounds obvious then you’re not Travis, who spent precious seconds on Sunday attempting to as his undead neighbor tried to chow down on him.

“You’re sick,” Travis told his former friend.

“Arrrggnnrraggnnh,” Peter responded, a few moments before Daniel blew off his face with a shotgun.

The challenge of letting go of the old ways is a core theme of “Fear the Walking Dead,” as the fictional Angelenos try to adapt to the swift, unexplained collapse of order and normal human behavior. Sunday’s episode was especially thick with the weight of history, an anchor that, amid cataclysmic upheaval, can leave people vulnerable to ghastly fates.

Though we got glimpses of practices that we know as standard operating procedure in “The Walking Dead” — strangers coming together to form makeshift families, say — Sunday was largely about people straining against the new changes demanded of them.

For Travis the humanist, that translated as a refusal to recognize the inhumanity of the walkers, something you think would’ve sunk in after he watched Nick run over Calvin a few times without killing him.

For Daniel, haunted or perhaps demented by his experiences in what I’m guessing was the Salvadoran Civil War (more on that in a minute), it was a stubbornness to embrace the safety-in-numbers strategy that will come in handy later.

For Nick, it was a failure to accept that a zombie apocalypse is no place for junkies. For Chris, it was a failure to accept that it’s no place for crybabies, either.

That said, they all deserve a break for now — only a few days have passed in the world of the show. If everything was fine on Monday and then my friend tried to eat me on Wednesday, I’d probably be pretty whiny, too. As Tobias the wise nerd once noted, when society collapses, it collapses fast. And while our civic structures can seem rock solid, “The Walking Dead” franchise wants us to ponder whether they’re flimsier than we believe.

In what seems to be the M.O. for this series, this episode picked up minutes after where we left off two weeks ago, as Travis and family tried to wait out a riot that showed no signs of settling down, what with the fire next door and the cops mauling each other and all. Mrs. Salazar injured her leg during the flight toward Travis’s miraculously unmolested pickup truck, necessitating both a side trip to the hospital to confirm that everything had gone to hell and, later, a tension-raising dip into Nick’s opiate stash.

Back at chez Clark, the family played Monopoly and reminisced about the night Daddy never came home. Zombie Pete lumbered around outside and the dog of the episode title showed up, covered in something else’s blood. (His would flow soon enough.) Nick remembered a shotgun at the neighbors’ house because he tried to steal it once. (Addicts are mostly liabilities when things get tight but they have their moments.) Soon everyone was in the backyard maze with Susan the undead Minotaur.

We’ve discussed this series’s reliance on tired horror tricks and Sunday’s episode was no different, from Mrs. Salazar’s suspense-amping injury to the silly maze scares. (Where are the shotgun shells?! Oh no we left them in the other house!) But what “Fear the Walking Dead” does handle with nuance are the family dynamics, the way it illustrates, for example, how the death of the Clark paterfamilias shattered that family — Nick’s addiction, Alicia’s surly disaffection — without being overbearing about it.

As for the Manawas, Chris is petulant and annoying, sure, but that’s mostly because he’s a walking ball of resentment over his father’s new family. Meanwhile not even an onslaught of the undead is enough to keep the divorced couple, Travis and Liza, from relitigating old points of contention in the kitchen, though neither of them know yet that Liza’s medical school dreams are deader than old headless Pete and the dog he ate.

And then we have the Salazars, whose rift is of the generational variety. In them we see the classic scenario of the adult child exasperated by her parents’ apparent bull-headedness, but here it comes with a possible twist. There were lots of allusions on Sunday both to the family’s roots in El Salvador and some sort of dark past. “Your father and I have been in worse situations,” Griselda tells Ofelia.

She could be referring to the Salvadoran Civil War, a horrifically bloody conflict that lasted from 1979-1992, pitting the military-led government against a variety of guerrilla groups. It’s only a theory, but it could explain Daniel’s apparent hostility toward the military — “it’s already too late,” he says when they arrive later — as well as the harder edge that emerged on Sunday.

Previously I compared him to Hershel Greene, the judicious family man from early seasons of “The Walking Dead,” but Daniel was revealed to be more ruthless than your average barber as he shotgunned Peter without compunction and later derided Travis as “weak” for not clobbering Susan with a hammer. “Good people are the first ones to die,” he tells his daughter, seemingly based on experience. So what are we to make of that fact that he’s still around?

The series is setting up Daniel and Travis as opposite sides of the human coin, Daniel’s coldblooded protectionist impulse versus Travis’s openhearted communitarianism. (Madison splits the difference, which probably means she’ll be the most effective leader of all.) So far it’s Travis who looks like the sap. “The cavalry’s arrived,” he tells Madison after the troops show up to take out Susan and take over everything else. “It’s gonna get better now.”

We, of course, know it won’t. But as for how we get from here to there — how things get so bad when the authorities were involved so early, and to what extent they were responsible for the ruin to come — remains to be seen.

A few thoughts while we pause for some shameless cross-promotion

• Toward the end of the episode, there was a lingering shot of a low-flying plane that seemed to be in some sort of distress. Any chance that ends up being the site of the latest “Walking Dead” spinoff, the stand-alone special set on a jet that was announced a couple weeks ago?

• If we’re staying here tonight, Madison tells Travis, you’re taking care of Peter. Talk about a bummer of a honey-do list…

• Speaking of chores, it was a fun touch to have Travis and the other neighbor still holding on to old habits, putting out their garbage as if someone’s actually going to pick it up. “Good morning, Susan,” Travis said to the growling zombie at the fence, which I enjoyed.

• Is it me, or is Alicia oddly uncurious for such an intelligent and confrontational girl? Let’s see, your boyfriend and everyone at your school have been laid low by a mysterious illness, you’ve seen cellphone videos of people shaking off police gunfire, you just watched your neighbor attack your other neighbor as your mom turned away, and … nothing? Just a few sarcastic quips about Monopoly and that’s it?

• “I’ll never leave you again,” Travis tells Madison. Sorry Trav, but that’s not how this franchise works.