[b]::THEORY::[/b] So in the live action trailer those marines are talking about insurgents and such. To me the key dialogue comes when they said a Comm Station is down. These 3 marines will go to the Comm station and be attacked by the spec ops covenant force aka their initial raid party used to sever communications. These marines will be slaughtered and be the cannon fodder used to start the story. Now this is where my theory comes in, The first mission will be training and it will be Noble team reporting to that comm tower and have their first run in with the Covies(I know this is a lot of peoples theory but im going a little farther so hang on lol) I believe this will be the end of training and you find out that in the training stage you were playing as the original #6 of Noble team and you play as him/her and you die in the end of it. In comes "The Battle Begins" Trailer where the new #6 arrives and you take over from that point as that character. I havent read any of the Halo books so i dont know the exact info. Im going on this but didnt Jun(Sniper?) say something along the lines of "Is this our [b][u]NEW[/b][/u] #6?" and is answered with an "affirmitive". Once again if i misquored just tell me and ill edit this post away