Also, I think that for the last four missions, they weren't originally supposed to be split up like that. Chronologically it doesn't make sense, as at the end of Uprising, we see Tartarus's Phantom landing, but at the beginning of the next mission (High Charity), we see it [i]leaving[/i], which means that Uprising and High Charity take place simultaneously, which doesn't actually make any sense, given that the Arbiter and the Master Chief should have been teleported at the same time, which means that Gravemind and Uprising should be happening at the same time.