Robot dinosaurs, rogue AIs, and the doom of the human race: Everything you need to know about Horizon Zero Dawn before playing Horizon Forbidden West

Horizon Forbidden West, due out on February 18, is the sequel to Horizon Zero Dawn, an RPG set in the post-apocalyptic American Southwest where by robotic dinosaurs roam the land. Humanity doesn’t know where they come from or understand the technology that powers them, having returned to a Neolithic way of life, though in some areas you see they’ve advanced to Bronze Age technology. That’s not exactly a remnant of Earth as we know it.

So what’s the deal? How did this all happen? If you’re planning to jump into Horizon Forbidden West and haven’t played the first game — or you haven’t played recently and need a refresher — here’s everything you need to know to understand what’s happening in Horizon Forbidden West.

Spoilers for Horizon Zero Dawn follow.

Aloy is an outcast, which gives her a unique perspective

You play Aloy, an outcast from the Nora tribe who fights — and even tames — these robotic dinosaurs. She was cast out when she was a newborn, and was entrusted to another outcast named Rost. It was forbidden for Nora to even speak to an outcast, and she grew up isolated from the tribe, not even knowing why she was cast out.

And that’s crucial to the rest of the story. The Nora avoid the rusting remnants of the old world, viewing it as cursed —they believe the Old Ones served the Metal Devil, and their cities were tainted and left to ruin because of it. Even visiting such a ruin is reason to be cast out of the tribe. But Aloy is unafraid: as a young child she falls and finds herself in an ancient ruin, but instead of cowering in fear, she explores. She finds a Focus, a device that served the ancients as something akin to a PDA, a smart phone, and an augmented reality device all in one. The Focus lets her scan items, helping her track creatures, giving her insight into machines and technology, and allowing her — unlike the rest of her tribe — to interact with the ruins of the old world. Eventually, she even learns to “tame” hostile machines to help her.

Despite the fact that Aloy doesn’t quite believe in Nora ways, she’s desperate for acceptance into the tribe, because someone there can tell her why she was cast out. What crime was so terrible that the Nora would put an infant out in the cold? And what became of her mother? Only the Nora Matriarchs know.

There’s one way to gain that acceptance: when Aloy comes of age, she can enter the Proving, and if she completes the challenge she will be welcome into the tribe again. And if she wins the Proving, she’ll earn a boon from the Matriarchs — one request that they cannot deny. With this boon, she could finally get the answers she wants.

The Proving only leaves Aloy with more questions

Aloy spent her entire life training to win the Proving,  finishes in first place. But at the moment of her triumph, masked outlanders attack, specifically targeting Aloy. Many were killed and Aloy herself only survives because Rost — though forbidden from attending the Proving — was watching, and intervened to save her at the cost of his own life.

It’s here that Aloy gets her answers: she has no mother, but was born from the mountain itself. The Matriarchs found her as an infant inside the mountain. Some believed she was the child of All-Mother itself, but others believed she was a curse, left by the Metal Devil. Thus, she was cast out.

But in All-Mother mountain, the place of her birth, Aloy discovers a clue. When she approaches a great door in the mountain, it comes to life, scanning her and showing her a picture of a woman who looked like her, but older, with short hair. Could this be Aloy’s mother? Was she inside the mountain? But it announces its database is corrupted, and her access is denied. The Matriarchs take this as a message from All-Mother that Aloy must heal this corruption, and anoint her as a Seeker of the tribe, allowing her to leave their Sacred Lands to hunt down the killers, cleanse the corruption, and perhaps finally find answers to her origins.

The Eclipse and the rebirth of ancient machines

The killers who attacked the Proving are known as the Eclipse, a faction of Carja who wish to overthrow the Sun King. While the current Sun King favors peace between all tribes, the previous Sun King raided other tribes for slaves and prisoners to sacrifice to the Carja sun god. Chasing the Eclipse puts Aloy in the middle of a complicated political situation spanning nations… quite a change from being a child outcast from own tribe.

But this is about far more than politics: the Eclipse have been digging up ancient machines and brought them back to life with the help of Sylens, a Banuk eager to learn about this ancient technology. They command robotic armies, filled with Corrupters that can control other machines and massive, unstoppable Deathbringers. And, worst of all, they’ve awakened an AI called HADES… which is intent on reclaiming its role as destroyer of the world.

HADES recognized Aloy as a threat, and targeted her for extermination, leading to the massacre at the Proving. But where did HADES come from… and how could it be stopped?

Aloy’s Focus holds the answer by allowing her to access ancient data files hidden in the ruins… and finally learning how the civilization of the Old Ones fell. AI-powered military robots created by Ted Faro went rogue and started systematically wiping out the human race. They could self-replicate and convert biomatter — living things — into fuel. Out of control, they were predicted to destroy every shred of life on Earth within 15 months.

Project Zero Dawn was a final effort to save everything

Elizabet Sobeck — the woman whose image Aloy saw in All-Mother mountain — had a solution. There was no way to stop the machines, but Project Zero Dawn aimed to preserve the the seeds of civilization to be born anew.

AIs were programmed to watch over the destroyed world. They would brute-force through the encryption on the Faro robots — a process that would take generations of human lives, time that they didn’t have — and shut them down, then terraform Earth into a green, living planet again. These AIs held an archive of all human knowledge, and when the Earth was ready for inhabitants again, it would clone animals to inhabit it, and eventually clone humans, educate them, and provide everything they needed to build anew.

One of those AIs was HADES, which was designed as a reset button for the world. The primary AI, GAIA, was designed to be nurturing, and would keep trying to fix things even if terraforming efforts failed to create a stable ecosphere. If that happened, HADES would take control and wipe the slate clean so they could start anew, eventually creating the perfect world for humanity to flourish again.

The death of Project Zero Dawn

Clearly Zero Dawn didn’t work… at least not entirely. The Earth is livable and full of humans, but they know nothing of their past, and the robots that roam the world are becoming increasingly violent.

Part of this comes back to Ted Faro. Perhaps he was burdened by guilt, perhaps he was driven by egoism, but he decided to delete the archives of knowledge that Zero Dawn painstakingly assembled so that future humans could be “innocent” without the burden of knowledge or the danger of technology. He then killed the senior members of Zero Dawn, and the AIs were on their own, without further human guidance.

All went well… for a time. The Faro robots were shut down. Terraforming efforts began, creating the robotic creatures that roam the world, which worked to cleanse the water and revive the soil. But the AIs broke free of GAIA’s control after receiving a mysterious signal — perhaps one we’ll learn more about in Forbidden West — and HADES set to destroying the world anew. In a last-ditch effort to stop HADES, GAIA destroyed herself in hopes it would destroy HADES as well.

It did not. HADES was injured but not defeated, GAIA was gone, and the other AIs were left to their own devices. (We learn what the AI HEPHAESTUS has been up to in Horizon Zero Dawn’s Frozen Wilds DLC, but know little of what happened to the others — and any of them might show up in Forbidden West.) With Sylens’ help, HADES convinced the Eclipse that it was a god, and used them to dig up old Faro robots and reactivate them.

But GAIA had one last trick up her sleeve: she made a clone of Elisabet Sobeck, her creator, and perhaps the only one canny enough to stop HADES. That clone was Aloy.

She had finally found her answers… only to discover she had never had a mother at all. Just as the Matriarchs believed, she was a child of the mountain.

HADES is defeated… but not dead

Sylens was purely motivated by a lust for knowledge, and when he found out HADES wanted to destroy everything, he searched for ways to undermine it. In that search, he found Aloy, caught up in Carja politics as she hunts for answers.

Together, they found a way to stop HADES: a program that would shut the AI down. But she had to get close enough first, and HADES was getting close to completing its plan. The AI took its army of Faro robots to the Spire, an ancient broadcast tower it could use to reactivate Faro machines across the globe and wipe out humanity for good.

Unsurprisingly, Aloy manages to rally the people of her time, defeat HADES, and stop the Faro robots. Life is saved.

But Sylens had his own goals… and they didn’t involve killing HADES. Instead of destroying the AI, the program trapped it in a cage of Sylens’ construction, and he intends to interrogate it and learn more secrets of the Old Ones.

We don’t know what will happen in Horizon Forbidden West, but it’s certain that some of these plot threads will come into play. Now you know the story leading into it so you’re ready to jump into the game when you start playing it today.

Originally posted February 11, 2022. Updated February 18, 2022.