Space.
Enormous and ever expanding, the universe contains all known living lifeforms that are alive, but there exists a powerful technology capable of wiping it all out... the Halo rings. Built by the ancient Forerunners, the Halo installations can be activated to send out powerful waves of energy to kill all sentient life... throughout all of space.
Space.
In one particular part of space there was a really big space ship called High Charity. It was kind of a space ship, but also kind of an asteroid, and also a city. There was a lot of aliens in it. These aliens were collectively known amongst each other as The Covenant, but to humanity, they were simply the Alien Bastards.
Space.
Inside the High Charity... council was in session.
"There shall be order in this court," shouted the holy Prophet of Truth. Silence fell over the previously angered grunts and elites and brutes and other aliens in the court room.
Standing before the three holy Prophets (there was also Mercy and Regret) was Thel'Vadamin, the elite who had lead the Alien Bastards in their previous incursion to try to activate halo (it didn't work when Master Chief blew them up, more on that later.) His head was hung low in shame and there was kind of a gurgling in his throat because he wasn't happy.
"Thel'Vadamin," continued Truth, "you stand trial before us today because you failed to activate Halo and allowed it to be destroyed at the hands of an unholy demon."
"Noble Prophet of Truth," Thel'Vadamin started, "it was not that simple-"
"Shut the fuck up," Truth said, "I am speaking now." He sighed. There was an awkward pause as Truth realised he didn't actually have more to say. He coughed. "Well, speak, fool, defend thy self!"
"It was not just the demon, lord," the alien dude continued (his name is really hard to spell so I'll just call him that until I can call him what he's called later.) "None of us could have predicted the Flood."
Hushed whispers took over the council chamber. The Flood.
"What happened with the flood was... indeed unfortunate," Truth said. "But that is no excuse. Though the water made it difficult for you to reach Halo's control room in time-"
"What?"
"The... flood."
The alien dude would have frowned if he had a mouth like ours but instead he just kind of wiggled his squid face thing. "Not the flood, Lord. The Flood. The other Flood. The flood was nothing we could not handle with banshees, but the Flood was a different matter altogether."
"Ah!" Regret said. "He speaks of the Flood."
"Nay," interjected Mercy, "he refers to the flood, the one that prevented access to Halo's lower tunnels."
Truth held up his hand. "Mercy, do not be ridiculous. He indeed speaks of the Flood that you are ignoring, the Flood that wiped out most of our forces, and indeed the human forces as well. The Flood that Regret refers to. The flood that you refer to was nary a foe so dangerous as The Flood, as the flood could be defeated with our superior technology, while The Flood are immune to our attacks such as these."
"Indeed," Thel'Valadim said. "The Flood flooded the tunnels which the flood had flooded."
Truth stroked his beard. "Now I am confused again. Did the flood flood the flooded areas before The Flood, or was it The Flood who overtook the flood in flooding the flooded zones?"
"Enough!" shouted a council Prophet from the jury. "Just kill him already!"
Truth nodded. "Indeed, I grow tired of this talk of the flood."
"You mean The Flood," the alien dude said.
Truth squinted, then nodded at the brutes. "Lock him up. And punch him a few times too."
Space.