Destiny: Lore

Chapter 16: Curse of Osiris

After the awakening of the Traveler, Ikora calls the Guardian to the Tower, explaining that the Hidden have discovered a damaged Ghost on the intact remnants of Mercury. Ikora identifies the Ghost as Sagira, belonging to her former mentor, the legendary warlock Osiris, who had been exiled from the City years before the first game. Traveling to Mercury, the Guardian locates the gateway to the Infinite Forest, a simulated universe created by the Vex inside the planet's core, but is unable to enter; The Guardian then comes under attack from Vex constructs from various points in time. Brother Vance, the fanatical leader of the Followers of Osiris, directs the Guardian to a hidden temple in an abandoned radio tower in the EDZ on Earth, with a modified Vex device that can restore Sagira. The device temporarily merges Sagira with the Guardian's Ghost, allowing them to access the Gateway to the Infinite Forest.

Inside the Forest, the Guardian encounters reflections of Osiris created to explore its different simulated realities. The reflections explain that in the past, mercury had been a garden world, shaped by the Traveler, until the Vex arrived and created the Forest in Mercury's core. The Guardian witnesses a simulated future created by Panoptes, the Vex Mind that controls the Infinite Forest, in which Light and Darkness are no longer, all non-Vex life has been wiped out, and the Sun is darkened. Osiris' reflections claim that they have been unable to find a way to prevent the dark future, but believe that the Guardian may be the key to stopping it.

Ikora directs the Guardian to the Pyramidion, a Vex construct on Io, which contains the map to Panoptes' lair. Following the Pyramidion's data back to the Forest and battling Red Legion simulations within, Sagira discovers that that map changes too quickly to find Panoptes. The Guardian travels to Nessus to obtain the core of a smaller Vex Mind to boost Sagira's processing power. Returning to the Forest's simulated past on a tip from Ikora, the Guardian combines the map data with Panoptes' algorithm from the moment of it's creation, allowing Sagira to locate Panoptes' lair. At that moment, Panoptes itself arrives and forcibly separates Sagira from Ghost before ejecting the Guardian from the Forest.

Regrouping at the Tower, Ikora accompanies the Guardian back to Mercury, where she forces open the gateway to allow the Guardian to return to the Forest. Upon reaching Panoptes' lair, the Guardian fights through Panoptes' simulated legions, but is unable to damage the Vex Mind alone; Panoptes prepares to delete the Guardian from the Forest when Osiris himself arrives to aid the Guardian. Osiris is able to hold Panoptes at bay long enough for the Guardian to weaken and then destroy it, freeing Sagira and preventing the dark future from occurring. The Guardian and Osiris emerge from the gateway, where Ikora invites Osiris to return to the City. Osiris declines, and bids farewell to his former student and the Guardian before returning to the Infinite Forest.