I think this would be a cool twist. After Master Cheif (MC) blows up the first halo he did not know that that flood had sneaked aboard the fighter he flys on. So when he gets to the space port the flood effection forms get off an start to attack people walking by so they do not get noticed. So while master cheif is getting of the ship half the space port is being turned in to flood. Now flood as a army they will attack soon. Mean while Johnson is walking around an notice that it is quiet to quiet so he starts to get his assault rifle an walks over to MC an tells him somthing is going on so MC is like FUC U i am tired u try blowing up a plant an getting the hell out of there. So he gets his gear an is weapon an starts to walk around. Then the lights turn off then they start to flicker MC like WTF i get back from blowing up a plant an come back to a space port that as people missing WTF. So they keep walking then cheif falls in a hole it is like 10 ft an wat is in the hole is somthing big an scary.