Deep Secrets of the Earth: Quest Walkthrough and Key Objectives

The Deep Secrets of the Earth quest serves as a pivotal mission in Horizon Zero Dawn, driving players into the heart of ancient ruins to uncover the true origin of Project Zero Dawn. As Aloy ventures into the underground facility beneath Sunfall, she discovers critical revelations regarding the ancient world and the cataclysmic events that brought about its downfall. Navigating this dangerous ruin requires a mix of stealth, puzzle-solving, and combat against heavily armed human cultists and dangerous corrupted machines.

Reaching the Underground Facility in Sunfall

To initiate the quest, Aloy must make her way to Sunfall, the stronghold of the Shadow Carja, and gain entry to the Citadel. After infiltrating the palace grounds, she locates a hidden secret entrance that leads deep into the subterranean complex known as the Zero Dawn Facility. Navigating down into the pitch-black elevator shafts reveals a massive, forgotten structure preserved from the ancient civilization.

Navigating Security and Clearing Shadow Carja Forces

As Aloy moves deeper into the complex, she encounters hostile Shadow Carja warriors guarding the ruins alongside corrupted machines. Utilizing stealth tactics and targeted elemental arrows allows players to eliminate these enemies efficiently without drawing widespread attention. Clearing out these rooms room-by-room is necessary to freely search the facility for security passes, audio logs, and datapads.

Restoring Power to the Facility Doors

Progress through the facility becomes blocked by locked blast doors requiring power restoration to proceed. Aloy must locate the holographic matrix puzzle room, where she needs to realign code rings to restore electricity to the door controls. Examining nearby audio logs provides the exact sequence needed to turn the rings correctly, unlocking the path deeper into the project's central archives.

Uncovering the Truth Behind Project Zero Dawn

Once power is restored, Aloy enters the central briefing room to view pivotal holographic recordings left behind by Dr. Elisabet Sobeck and her team. These logs reveal the grim truth about the Faro Plague and detail how Project Zero Dawn was designed to terraform and reseed life on Earth. Armed with this crucial knowledge, Aloy must secure a master override program and exit the facility before heavily armed reinforcements block her escape route.