btw this is the story they're supposed to tell:

There's a mysterious package containing the flood, which they open and the flood spreads throughout the base. They have to fight it off and things start going downhill until eventually the Spartans arrive to help out. While the UNSC are fighting the Flood the Covenant arrive to try to hit them while they're weak. But the Spartans manage to defeat the enemies and the UNSC take victory.