Cocytus

"[T]his place is...it doesn't have a name. We called it A-113."

- Arach of the Sophia

Cocytus, also known as A-113 or A113, was a small space station dating to the Golden Age in stationary orbit above Ceres.

History
The station's purpose is unknown, as any records of its existence did not survive the Collapse, but it contains "keyholes" that seemingly led to other dimensions. Crota captured Cocytus after the Collapse. As a result, its apertures became entrances to his throne world or some similar space, driving any who entered them to madness or worse.

The station was rediscovered by Dead Orbit who gave it its current designation and kept it a secret from the Tower. Sixty one days later a subsequent expedition there ended in failure: an Awoken ship from the Reef crippled the expedition's ship, the Sophia, and exploration of A-113's keyholes rendered most of the crew insane. The crew's Arach found a faded Ghost on the station and sent it back to the City with a request that Dead Orbit strike A-113 and the expedition from their records. Afterwards, the Awoken who destroyed the Sophia installed instruments on Cocytus to study the space that the keyholes led into. Notably, Reef intelligence does not know who this Awoken was.

After Ceres was annihilated in the Reef Wars, Reef forces moved Cocytus into a heliocentric orbit. Wary of the potential threat, they established an armed containment perimeter around the station and planted warheads aboard so it could be destroyed at a moment's notice.

When Crota was destroyed by The Guardian, Cocytus's portals ceased to lead to his throne, and instead somehow fell into the possession of the Nine. Five of the Nine began using Cocytus as a laboratory, using the station's third portal to convert their dark matter into "regular" matter, with the ultimate goal of producing living organisms from scratch. While the Nine could create (with increasing sophistication) basic atoms, crystals, and organic precursors, their two attempts at viable life failed almost immediately, and the portal fell mostly into disuse. Each sending was recorded by the Awoken forces still containing the station. Their own probes, sent through the same portal, immediately ceased to exist on crossing, presumably transmuted likewise into dark matter.

Trivia

 * A113 (sometimes A-113 or A1-13) is an inside joke, an Easter egg in works created by alumni of the California Institute of the Arts, referring to the classroom used by graphic design and character animation students.
 * "Cocytus" is translated from Ancient Greek as "lamentation," and is the name of a river flowing through the underworld in Greek mythology. It is also the name of the ninth and deepest level of Hell in Dante Alighieri's Divine Comedy.

List of appearances

 * Destiny
 * Destiny 2
 * Joker's Wild