Subnautica: Below Zero

Two years after the events of the original game, the Alterra corporation that originally crashed the Aurora on planet 4546B had built several bases on the planet for research on the Kharaa bacterium, and on the alien precursor race, dubbed Architects, that had studied the bacterium prior. Xenologist Robin Ayou smuggles herself onto the planet in a frozen sector named "Sector Zero" to investigate the circumstances of her sister Sam's death, which Alterra claims was a result of "employee negligence." During the past year, Alterra had recently withdrawn all of its personnel, allowing Robin to land on the planet.
Shortly after landing, Robin picks up a distress signal and goes to investigate it, discovering an alien sanctuary containing the digitized consciousness of a living Architect. Desperate for a new storage medium as the sanctuary's power is running out, and after an apparent misunderstanding, the Architect downloads itself into Robin's brain. Angry at it for intruding into her mind, Robin initially tries to ignore it, but soon agrees to help it, now introduced as Al-An, to construct a new body to transfer into. To do so, Robin combs the sector for alien installations and artifacts to find the necessary components and materials. Al-An explains that it did not try to contact Alterra for help before because it believed Alterra's motivations did not align with its own, and did not want to risk them finding a way to its homeworld. During their search, Al-An hints that it was involved with the outbreak of Kharaa.
Meanwhile, Robin also continues her investigation into Sam's death. She encounters Degasi survivor Marguerit Maida several times, who is suspicious of Robin at first thinking she's with Alterra, but reveals her part of the story in return for disabling Alterra surveillance of the sector. Robin searches the abandoned Alterra facilities, and finds out that Alterra had discovered the corpse of a leviathan frozen in ice that was still infected by Kharaa. However, instead of destroying the Kharaa, Alterra decided to research the bacterium for useful applications. Fearing another outbreak and concerned that Alterra would use the Kharaa to develop bioweapons, Sam decided to sabotage the project. Encouraged and helped by Marguerit, she synthesized and stashed away a cure for the Kharaa, then used explosives to collapse the cave holding the leviathan, while Marguerit destroyed the lab holding Alterra's Kharaa samples. However, Sam was inadvertently caught in the blast and killed by falling rubble along with another person. Unable to determine the cause of the cave-in, Alterra wrote off Samantha's death as a result of negligence. Using this knowledge and some maps and clues, Robin recovers the cache of Kharaa antidote that Sam had made and uses it to neutralize the Kharaa infecting the frozen leviathan, finishing her sister's business and preventing Alterra from continuing their project.
Alongside this, Robin is eventually able to recover all of the components necessary to build a new body for Al-An, and fabricates it at an alien facility. After transferring itself to the body, Al-An reveals that it was one of the lead scientists researching a cure for the Kharaa bacterium; it disobeyed orders by trying to hatch Sea Dragon leviathan eggs, resulting in the research facility being destroyed by the Sea Dragon egg's mother and the Kharaa being released onto 4546B. Al-An decides to return to its homeworld in order to see for itself what had happened to the other Architects, as well as to atone for its past mistakes. It activates an Architect phasegate and Robin agrees to leave 4546B with it, uncertain of what they will find there.