Today Bungie hosted a livestream to introduce Destiny 2 players to the forthcoming expansion, Curse of Osiris. Destiny 2's first expansion will take Guardians to the half-devoured, Vex-riddled planet of Mercury. And on that planet they'll hunt for the legendary exiled Warlock, Osiris. To help set the scene and start the livestream proper, Bungie community guru DeeJ debuted Curse of Osiris' prologue cinematic trailer.

The prologue trailer for Curse of Osiris gives introduction not only to the Warlock himself, but also to his unique Ghost companion Sagira. Osiris is hunting for something on Mercury within the Vex stronghold at the planet's core. His coopted Vex technology allows him to explore this Vex installation, named the Infinite Forest, though clearly not with ease. Sagira, a much more important character than previously expected, is clearly not thrilled about the endeavor.

During the livestream it was confirmed that players will be venturing forth in search of Osiris and Sagira - Destiny's first named and voiced ghost outside of the player's own - at the behest of Ikora. Ikora is Osiris' disciple and is looking for renewed hope following the events of the Destiny 2 campaign. Guardians will naturally grow further involved in Osiris' mysterious goals and the Vex plan revolving around the Infinite Forest at Mercury's core in the Curse of Osiris campaign.

The Curse of Osiris trailer itself takes place within the reality-shifting Infinite Forest, which should explain the odd events therein. The Infinite Forest is a Vex tool used to simulate all realities and the fight Osiris steps into is one such simulation. His bracers are lined with Vex pieces, which allow him to manipulate Vex technology - kind of.

Other Curse of Osiris announcements made during today's livestream includes the reveal of the new Mercury Lighthouse social hub and Raid Lairs. Rather than release a unique raid with each new expansion, Bungie will release Raid Lairs with expansions one and two. They are extensions of the current raid Leviathan, each offering entirely new content but smaller than a full raid. The second expansion is tentatively planned for spring.

Two more livestreams are planned for Curse of Osiris, one in each of the next two weeks. So expect more Destiny 2 Curse of Osiris information soon.

Destiny 2 is available now on PC, PS4, and Xbox One. Curse of Osiris releases on December 5 across all supported platforms.