Netflix is ending 2017 by deciding to scare the pants off its subscribers with a new round of Black Mirror, Charlie Brooker's technophobic look at a twisted future. The series examines the dangers of weaving technology too tightly into the fabric of society in a Twilight Zone-like anthology setup, often turning viewers' opinions from "Hey, that gadget looks cool!" to "I am never turning on my phone again" in the matter of an hour or so.

But none of Season 4's episodes are as terrifying as "Metalhead," a tense hour that pits one woman named Ellen (Maxine Peake, in a brilliant performance) against a security machine that would almost look like a cute robo-puppy if it weren't for the fact that it hunts its targets down with relentless gusto and blows the tops of their heads off with a shotgun that's attached to its front paw. It's a tale of desperate survival in a post-apocalyptic world, riding a wave of suspense through its run and ditching the intellectual undertones of other Black Mirror episodes for something more animal and instinctual.

It's also delightfully toward the horror end of the spectrum, up there with Black Mirror classics like "Playtest" or "White Bear" in terms of sheer terror. But its influences go a lot further back than that.

Maxine Peake, Black MirrorMaxine Peake, Black Mirror

"When I first got the script, there were so many things that we talked about in terms of what it made us think of, a lot of it was old horror," director David Slade tells TV Guide. "Classic things, I think Charlie Brooker mentioned to me Steven Spielberg's Duel and Jaws, and I was like, 'Yup, got that! I can see that completely."

Slade also brings up one his main inspirations, The Texas Chainsaw Massacre, as a major influence, and compares the instant brutality of Leatherface to what the robo-dog does early on in order to establish it as a threat. Or in Slade's words, "The moment the robot shows up, it should shoot the guy in the f***ing head and kill him."

Those classic films also had an effect on the episode's look. "Metalhead" was shot in black and white, a first for Black Mirror, and its implementation is highly effective at stripping down the story to its crux and creating a bleak, dangerous world.

"I don't know if there's another Black Mirror that is literally after some big event has happened — where we walk into a world that has great weight to it, that it's heavy, that everything is distressed, the people are just barely banding together, " Slade says. "And it just seemed to me that that weight could be added to by having everything look like it was hewn out of silver. There was no really good reason to be stylized about the color of the thing, also there was the issue that we had, the character that was an analogy of a dog, but essentially was a machine."

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The bleakness set by the (lack) of color palette is further stripped down by the fact there's no exposition to explain what's going on. Viewers are simply dropped into this world where humans appear to have been nearly wiped out and military-grade security robots guard valuable stashes. While the story of "Metalhead" doesn't require any set up — it really is just about one woman trying to survive the relentless pursuit of a metal beast — viewers will inevitably want to know how the world got to this point. But that's not going to happen, because even the people making it didn't know.

"To some extent, we had so much story and character to work with, it didn't matter [what had actually happened]," Slade explains. The crew did build out ideas for where Ellen's group lived to give actors something to build upon for their performances, and they set up certain rules for the look of the land — the vegetation wasn't touched but all the metallic things were — and typical ideas were bandied about for what happened, including a biological event or a general apocalypse. But nothing concrete was decided upon because "Metalhead" was only about these moments between Ellen and the robo-dog.

"That humanity had gotten to the point that they were using military robots to protect their merchandise seemed more important," Slade says. "And it doesn't seem that far fetched. We had so much there already that we never got around to talking about the event."

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Of course there's a slight Charlie Brooker twist at the end, when we discover what it was Ellen was willing to risk her life for. We knew she and her friends were searching for an item to help a young boy back at camp cope with what apparently were his final days, and in the final shot, we see the object that ultimately cost her life as well as those of her friends: a teddy bear.

But that wasn't always what they were looking for. Brooker originally thought the quest item should be something like a GameBoy or other gadget, but Slade had other ideas.

"No, no, no. We have Maxine, it has to be something soft," Slade recalls saying. "It has to be something that you can touch, that you would hold to you, that would give you comfort."

That's the punctuation on the show's message, which Slade says is, "Don't abandon your humanity. I think that the most important thing we have is our ability communicate and love other humans."

And don't go snooping around warehouses guarded by unstoppable robo-dogs.

Season 4 of Black Mirror is now streaming on Netflix.