The Story of Subnautica 2 begins with the player en route to the desert planet Zezura aboard the Cicada starship. The ship carries 40,000 printable colonists intended for a new colony project. During the journey, the Cicada makes an unscheduled detour through an alien phase gate and crashes onto the moon Proteus.
Arrival
Upon crashing, the Cicada breaks into numerous wrecks scattered across the moon. NoA, an AI developed by Alterra to support colonization, begins printing the first wave of Pioneers. Their mission is to prepare the world for colonization and accumulate resources to print the stored colonists.
This first wave established Camp One, but the habitat failed, resulting in the death of all pioneers. NoA reprinted them from older states, erasing their memories of the failure. As pioneers continued survival efforts, they grew suspicious upon finding their own bodies and ruined habitats. Distrust toward NoA grew, leading to the formation of a cult named Jubilee, led by the pioneer Anita.
Environmental hazards proved severe. Sophie Boucher, the colony's surgeon, determined that Proteus's biosphere is saturated with heavy metals, causing fatal poisoning. Additionally, pioneers began exhibiting symptoms such as hallucinations, trances, and violent or suicidal behavior. This condition was dubbed "Masefield Syndrome" and associated with the massive World Tree, though its exact cause remained unknown.
The pioneers also encountered the Tailings, a sapient alien race and remnant of an older species. The Tailings aggressively defend their territory, experimenting on and killing pioneers while attacking seabases.
Tensions Rise
Jubilee and the Pioneers operated separately for a time. Jubilee rebuilt the ruins of Camp One, while Pioneers constructed other seabases. However, Proteus remained hostile to human life due to digestion issues, heavy metal poisoning, alien viruses, and aggressive fauna. These challenges crippled both groups.
Jubilee severed the cable to Sleep Bay 3 (a section of the Cicada where new pioneers emerged) to prevent NoA from using their food supplies to reprint colonists, although Sleep Bay retained some reserves. Later, an extremist pioneer named Nahema Nakota detonated an explosive beneath the Welcome Center.
Tensions escalated as Nahema protested NoA's methods, urging pioneers to abandon seabases and explore Proteus. Fascinated by the World Tree and local lifeforms, Nahema despised human encroachment. With help from Mantis and Chap, Nahema triggered an explosion at the Old Habitat, killing several pioneers and disabling their Biobeds to prevent reprinting.
Following the explosion, a pioneer named Ganzo led a group of eleven survivors to the Tadpole Pens to regroup. During the journey, Ganzo's wife Ruby and Tuba were lost. At the Pens, they found that Sophie and Nahema had taken the last Tadpoles and locked down part of the base. Stranded, the group headed to the Graveyard to find a blackbox left by Zip, hoping it contained an access key for the Tadpole Pens.
Inside the Graveyard Caves, intense heat exacerbated Masefield Syndrome, causing trances and hallucinations. All pioneers died from viral contamination and were marked "Do Not Reprint" by NoA, except for Twinkle, who voluntarily shut off her air supply to trigger an early reprint at the Hot Cave Basecamp. Upon waking, Twinkle convinced NoA to reprint Ganzo. They debated returning to Sleep Bay 3 but instead decided to pursue Jubilee.
The Chase
After the Old Habitat explosion, Nahema fled to the Tadpole Pens, stole a Tadpole, and departed for the World Tree. Suspecting Nahema planned to use the tree to kill all humans on Proteus, Sophie chased her in another Tadpole. Sophie left behind a ghost recording at the Pens, revealing that the Bloom and Masefield Syndrome are distinct; Masefield is caused by a Proteavirus infecting all living beings on the moon.
Sleep Bay 3
Over 25 years after the Cicada crash, the Qualified Investigator (QI) awakens in Sleep Bay 3 after being printed by NoA. Predicting the QI's imminent death from environmental pressure, NoA recommends using nearby Alterra technology to adapt. Instead, the QI finds the core of an Angel Comb, an unknown organism. Interacting with it grants gene mutations that allow survival on Proteus.
The PDA instructs the QI to take a Lifepod to the surface to send a distress call. After a rough launch and crash landing, the QI steps out to see the World Tree dominating the horizon.
