Folks, you are picking up clues to Halo 5 from Halo 4. Lets looks at some.
First, at the beginning when the good Doctor is being questioned, Someone is interested in John and it's not ONI.
Second, hints were given as to just how much John feels for Cortona. No John won't say it or even cry. That's his Spartan training.
Third, the Composer and the Librarian. They made it a point to explain the her role and the Composer's function of digitizing people and then later restoring them.
Last a minor one, John removed his armor.
What do you get from this for Halo 5? Some unidentified group wants John for who knows what purpose. John will probably speak to the Doctor and figure out that the Librarian, with the Composer may be able to not only restore Cortona but make her REAL. The Chief will Armor up again and head back to the Fore Runner's planet. Fighting everyone that gets in his way!
This is just general happenings and not a story line but it makes sense to me based on what I saw in 4. Halo 6 will be an epic climax in which the lots of people die, Cortona becomes real and John finally shows his face.
