you see i've read a few theories to halo 4's plot and they mostly entail, master chief and cortana crashing onto a forerunner built world and beaing atacked my a local flood infestation, but i see this as farefetched as the halo 4 teaser trailer is supposed to give away a clue to the plot of the game, so i think you are "abducted" by an outer galexy forerunner ship as by the ominous cyan glow that the "ship" as i will call it to avoid complication, gives off, so anyway they get abducted or happen to crash into this massive forerunner ship and are attacked by the surviving froerunners which didn't die when the halo's where activated becasue they were out of the galexy and the halo arrays effect radius and have came back to the milky way to serve justice upon the chief, as they destroyed the halo arrays and the ark (the fact that the forerunners would be mad is shown by how 343 guiltyspark tries to kill the chief for attempting to destroy the ring).. so master chief and cortana have to ascape the forerunner, this in my opion would give the most action packed and exiting campain :) thankyou and i welcome any feedback.