Storyline

This article is about the Storyline in Below Zero. To see this subject's article on the Subnautica Wiki, click here.

The Aurora crashes within The Crater on Planet 4546B, there are several survivors but all aside from Ryley Robinson are dead within 3 hours.
Ryley Robinson becomes infected with Kharaa and is unable to disable the Quarantine Enforcement Platform.
Avery Quinn of the Sunbeam trading ship attempts to rescue Aurora survivors but his ship is destroyed by the Quarantine Enforcement Platform.
Ryley Robinson sets out to discover more of Almanac remnants in order to cure himself.
Ryley discovers the remnants of the Degasi crew.
Ryley discovers the Disease Research Facility, Alien Thermal Plant and likely also discovers the various Precursor Caches.
Ryley discovers the Primary Containment Facility and meets the captive Sea Emperor Leviathan.
Using native flora Ryley creates Hatching Enzymes and hatches the five remaining eggs of the Sea Emperor Leviathan.
The Sea Emperor Leviathan's children disperse, leaving through a warp gate.
Ryley Robinson constructs the Neptune Escape Rocket and likely returns to Alterra. The Sea Emperor Leviathan dies a short time after the rocket is launched.
After Ryley returns Alterra learns of the value the planet holds.

Two years after Ryley escapes 4546B,^[1] The Vesper is installed in orbit for research.
Robin Goodall and Jo Jeffreys are stationed in Sector Zero researching the local environment.
Jeffreys suddenly disappears.
Robin Goodall searches for Jeffreys at Alien Research Site Zero, finds his PDA and heads back to Research Base Zero to shelter from an oncoming electrical storm.
The extreme weather conditions trigger an avalanche, covering Research Base Zero and when trying to get back to it the ice below Robin's feet breaks and she is forced to swim out through a tunnel.

References

↑ Marguerit states she has been on 4546B for 12 years, and taking into account that the Degasi crashed a decade earlier when Ryley Robinson was in the Crater, it is obvious that two years have passed since the events of Subnautica. The Steam description labeling "one year" is likely a mistake.