With Bungie handing the keys to the Halo franchise to Microsoft, the game developer sets its course on a new adventure with publishing partner Activision.

To celebrate its past, Bungie has released a nearly hour-long documentary that explores the "Brave New World" ahead of them. In a lot of ways, it's like starting over, Bungie employees note. Halo has become such a "sure thing" that Bungie has now become an unknown. The video includes a few hints at their game, including the image above.

Watch: 'O Brave New World,' Bungie looks back and into the future »