The cover art of the newly announced Halo 5: Guardians already revealed its first secret: you have to squint to see it on the breast of the armor of the mysterious Spartan who will possibly be the game’s new protagonist.
You can see a zoomed-in image below, and that’s definitely the emblem of the ONI, the Office of Naval Intelligence, the shady intelligence arm of the UNSC Navy. The alternate version of the emblem also seems to be portrayed on the helmet, even if it’s harder to tell since only part of it is shown.
Of course this could mean several things and indicate a few existing characters in the Halo lore that could fit the part of the game’s protagonist, possibly looking to hunt down Master Chief, but it’s definitely a good start speculating on, isn’t it?
Update: Halo franchise Senior PR Manager Rob Semsey denied on Twitter the possibility that the Spartan could be Cortana.
Update 2: Franchise Development Director Frank O’Connor also added on NeoGAF that “it’s not Palmer and it is not a girl.”