Guerrilla Games has become a key developer for Sony over the last two console generations. The studio's pivot from Killzone to Horizon Zero Dawn was a big success, leading to development on Horizon Forbidden West as a tentpole PlayStation 5 release alongside the PlayStation VR2's upcoming Horizon Call of the Mountain. Given how hard Sony pushed Forbidden West's marketing, loose threads at the end of the game are clearly gearing up for a third entry.
Not much speculation is required to reach this conclusion, as Forbidden West's director Mathijs de Jonge has teased a third Horizon game. This sequel's path is clear. Mechanically, Guerrilla will add an even larger variety of robotic animals to fight, and possibly more movement options akin to Aloy's Pullcaster and Shieldwing glider. Its narrative progression is also obvious, though the developer should make sure it gives prominent attention to HEPHAESTUS. Spoilers for Horizon Forbidden West ahead.
Why Rogue AI Impacts the World of Horizon
The Horizon franchise is about what happens after the end of the world, and what humanity is leaving behind for future generations. Its conceit posits that the human race comes together and stops climate change, but in doing so props up a powerful corporation that pivots to military tech. Under the direction of CEO Ted Faro, Faro Automated Solutions (FAS) develops a Chariot line of robots able to self-replicate using biological matter as fuel. When FAS loses control of its war machines, they replicate endlessly and strip the Earth of all life in what becomes known as the "Faro Plague."
After receiving a briefing about humanity's hopeless situation, Elisabet Sobeck spearheads the hail mary Project Zero Dawn: recruiting the smartest minds from across the globe to develop an artificial intelligence capable of reseeding life after extinction - with the emotional capacity to decide what's right for all. This AI, named GAIA, was successful. Its host of sub-functions (named after Greek gods) were capable of doing everything from shutting off the Chariot robots to designing and building machines that fixed the ruined land, sea, and air.
However, Faro deleted GAIA's APOLLO database containing all human knowledge so that future generations wouldn't know about his culpability in destroying the world, leading to a tribal age seen when the events of Horizon Zero Dawn begin. Machines around the world also begin suffering from "the derangement," which Aloy learns is the result of GAIA destroying herself to keep a mysterious signal from activating the ecosystem-destroying failsafe HADES. This signal gives all GAIA's sub-functions sentience, and each AI scatters across the United States.
HEPHAESTUS' Prominence in Horizon Forbidden West
The brunt of Horizon Zero Dawn is spent dealing with HADES, which creates a cult that resurrects Chariot machines in an unwitting effort to restart the Faro Plague. During The Frozen Wilds DLC, Aloy meets HEPHAESTUS - the sub-function responsible for designing and building GAIA's terraforming machines. In its rogue state, the AI begins building more threatening "hunter-killer" machines to stop humans from hunting the very entities helping preserve the biosphere.
Once Aloy expels HEPHAESTUS from the Firebreak facility in Frozen Wilds to stave off machines corrupted by "the daemon," it gets a more active role in Horizon Forbidden West. HEPHAESTUS continues building dangerous hunter-killers, including Apex machine variants, and this has begun affecting entities like the Utaru Land-Gods that help seed crops for the people of Plainsong. With the world coming apart at the seams due to ecological disasters, Aloy learns from a copy of GAIA that they need this powerful sub-function to build new machines capable of stabilizing the biosphere.
After a few encounters, Aloy and her friends come up with a plan to recapture HEPHAESTUS before the rival Far Zenith faction can bolster its own GAIA copy. They fail, and the Far Zeniths claim this sub-function while killing Aloy's oldest friend Varl. However, while enacting a plan that releases HEPHAESTUS so it can build machines like Slaughterspines to combat Far Zenith tech, Aloy learns the faction merely wanted to escape the encroaching threat of a new entity named Nemesis. At the end of the game, Aloy's group heads off to recruit allies for a bigger fight; GAIA only missing HEPHAESTUS and HADES.
Why HEPHAESTUS Would Be a Better Ultimate Antagonist than Nemesis
Nemesis is introduced in the eleventh hour of Horizon Forbidden West, recontextualizing the events of the game but also clearly establishing a threat more dire than the Far Zeniths. This faction was comprised of old-world humans - the richest and most powerful - who fled Earth to start an intergalactic colony rather than take a chance with Project Zero Dawn. During that trip its members were able to essentially give themselves immortality through genetic experiments, but Carrie-Anne Moss' Tilda van der Meer tells Aloy that Nemesis was a failed attempt at digital immortality.
The project aimed to recreate the minds of every Far Zenith member so they could be uploaded to new forms, but when this failed the system was left abandoned, eventually fusing into one vengeful and sentient AI wanting to destroy its creators. It turns out Nemesis sent the signal that led to GAIA's sub-functions going rogue, so it kickstarted the events of the franchise. However, HEPHAESTUS would be a more fitting final antagonist in the third Horizon game.
As of this writing, it's unclear whether Aloy and her friends will recapture HEPHAESTUS between games; though this task would be difficult given the entity is cautiously spread throughout the Cauldron network building new machines around the globe. Making the rogue AI a side-thought in favor of Nemesis would be a mistake, as its presence since The Frozen Wilds makes it a relatively developed antagonist with a personal vendetta against Aloy for stopping its efforts on numerous occassions.
One way Guerrilla could give both antagonists their time to shine is by making HEPHAESTUS more of a "twist" final boss. Nemesis is a powerful, if abstract, foe. Much of Horizon 3 could be spent preparing for it, but when it appears a plot thread from Forbidden West could subvert its threat. GAIA is unable to re-assimilate HEPHAESTUS without the power of multiple sub-functions, saying she would otherwise be at-risk of getting assimilated herself. With the entity constantly growing smarter as it zips around the Cauldron network, it could become more powerful than Nemesis and absorb its capabilities just before the Earth is attacked. This way, Nemesis' power would facilitate a suitably epic final act without abandoning the stronger narrative lost by not using Horizon's main recurring antagonist.
Horizon Forbidden West is available now on PS4 and PS5.