Subnautica story recap

The original Subnautica (released January 23, 2018) follows Ryley Robinson, the Non-Essential Systems Maintenance Chief aboard the Alterra Corporation ship Aurora. This article covers the full plot for players who want background before playing Subnautica 2.

The Aurora

The Aurora is an Alterra Long-Range Capital Ship, roughly 1,280 meters nose to thrusters and 500 meters tall. It carries a crew of 157 across four divisions: 23 command staff, 85 engineers, 40 support crew, and 9 passengers. Its primary mission is phasegate construction in the Ariadne Arm, with a secondary objective to search for the Degasi, a ship that disappeared in the same sector ten years earlier.

Captain Hollister commands the Aurora. As the ship passes near an uncharted ocean planet designated 4546B, an energy beam from the planet's surface strikes the vessel, causing it to break apart. Hollister dies controlling the ship's descent to minimize casualties. Ryley escapes in Lifepod 5 and is the sole survivor on the planet's surface.

Surviving crew and lifepods

The Aurora carried 50 lifepods. Twenty-five managed to deploy before the crash; the rest were inoperable. Players can locate the wreckage of lifepods 2, 3, 4, 7, 12, 13, 17, and 19 during exploration, each containing audio logs that piece together the fates of their occupants.

• Lifepod 2 Contained CTO Yu and crew member Berkeley. Crashed 500 meters deep in the Northern Blood Kelp Zone. Both drowned attempting rescue dives.

• Lifepod 4 Landed in Reaper Leviathan territory near the Aurora's bow. One of the few pods with functioning flotation. The occupant sent a final distress call before being attacked.

• Lifepod 7 Located in the Crag Field. Contains a Markiplier bobblehead Easter egg. The pod's fabricator malfunctioned, producing hats and lab equipment instead of survival tools. The occupant was killed by Bonesharks.

• Lifepod 12 Contained crew member Danby, who had fraudulently passed his medical exams. Crashed in the Bulb Zone. Danby contracted the Kharaa bacterium and documented his deteriorating condition in his logs.

• Lifepod 13 Carried Mongolian Emissary Jochi Khasar. Hit the ocean at terminal velocity in the Northwestern Mushroom Forest. No survivors.

• Lifepod 19 Contained Second Officer Keen, who assumed command after Hollister's death and broadcast rendezvous coordinates to all survivors. Keen landed in the Deep Sparse Reef, became infected with Kharaa, and was killed by Warpers.

Planet 4546B

The planet is almost entirely ocean. Ryley discovers the remains of the Degasi crew through abandoned bases and audio logs scattered across multiple biomes. The three Degasi survivors (Paul Torgal, his son Bart, and mercenary Marguerit Maida) had been stranded for years, eventually building habitats at increasing depths. Paul and Bart died. Marguerit survived alone in the deep ocean.

The Kharaa bacterium

Ryley becomes infected with the Kharaa bacterium, an alien pathogen that had devastated the planet's ecosystem. The Architects (also called Precursors) brought the bacterium to 4546B for study. A containment breach at one of their research facilities released it into the ocean, infecting the local wildlife and ultimately killing the Architects who remained.

The Quarantine Enforcement Platform

The Architects built the Quarantine Enforcement Platform (QEP) on the planet's surface to prevent any infected organisms from leaving. The QEP shot down the Aurora, and when a rescue ship called the Sunbeam attempts to land, the QEP destroys it too. Players receive radio transmissions from the Sunbeam over the course of about three weeks, culminating in the ship's arrival at Mountain Island. Even if the player manages to disable the QEP before the Sunbeam arrives, the crew cannot land due to orbital debris from the Aurora wreck.

The Sea Emperor Leviathan

Deep underground, in the Primary Containment Facility at approximately 1,200 meters depth in the Lava Lakes biome, Ryley discovers the Sea Emperor Leviathan, the last surviving member of its species. The Architects captured it centuries ago after discovering it produced Enzyme 42, the only known cure for the Kharaa. However, the adult's enzyme was too unstable to synthesize at scale. The Sea Emperor's five unfertilized eggs held the key, but the Architects could not get them to hatch.

The Sea Emperor communicates with Ryley telepathically throughout the game, first as vague visions and later as coherent speech. It is over 2,600 years old and has outlived its species' natural lifespan by centuries.

The cure and escape

Ryley crafts a batch of hatching enzymes using seeds from four plants accessible through the facility's Alien Arch teleporters, plus a Sea Crown from the containment chamber. All five eggs hatch. The baby Sea Emperors release stable Enzyme 42 into the ocean, curing Ryley's infection and beginning the planet's ecological recovery. The adult Sea Emperor, having fulfilled its last purpose, dies shortly after playing with its offspring.

With the infection cured, Ryley disables the QEP and builds a rocket (the Neptune Escape Rocket) to leave the planet. He reaches Alterra space and receives a message informing him that he owes Alterra approximately one trillion credits for the resources he consumed during his survival. Everything from the food he fabricated to the rocket he built is billed to his account.

Game modes

• Survival The default mode. Players manage health, oxygen, food, and water. Death drops items.

• Freedom Identical to Survival but hunger and thirst meters are disabled. Focus is on exploration and building.

• Hardcore Permadeath with a single life. The PDA does not warn players about low oxygen.

• Creative Full sandbox. The player is invincible, resources are not consumed when crafting, and vehicles need no energy.

Commercial performance

Subnautica sold over 5.3 million copies and generated more than $108 million in Steam revenue. It spent about three years in Early Access (December 2014 to January 2018) and was widely praised for its blend of exploration, survival mechanics, and environmental storytelling. The game was built in Unity.