This is what I think will be Halo 3 for Miranda and Johnson, the Arbiter's part. It continues after the Arbiter asks 343-Guilty Spark where the arch is.
Disclaimer: I do not own the rights to Halo.
"The arch's location was not included in my data arrays. Is there anything else I can do to help you?" The Oracle replies somewhat apologetically.The Arbiter then looks at the ground and thinks to himself 'If the Prophets know the arch's location, they can still activate this ring and destroy us all.'
Just then, a platoon of Brutes burst into the control room to find the Arbiter and the two humans standing over Tartarus's corpse. A shocked expression crosses the face of the Brute Captain. "They have murdered the chieftain." He turns to his troops. "You know what he would expect of us." The Brutes become enraged and charge at their leader's killers. The Arbiter prepares to defend himself, finding only a plasma rifle of a fallen Elite. Johnson backs up. "Oh, Shit," he said. While Miranda struggles to pick up Tartarus's massive hammer, Johnson takes aim with the beam rifle. He manages to kill a Brute before jumping on to the control platform. The Arbiter charges towards the group of Brutes.Firing his plasma rifle, he manages to knock off one of the Brutes' helmets and hits another in the eyes, blinding him. He shoots the first Brute several times in the head, killing him.
The Captain remains untouched as he stomps toward Johnson. As the Brute slaps the beam rifle out of Johnson's hand, the Sergeant kneels down and puts his hand over his head. He looks up to find the Arbiter with an overheated plasma rifle held to the Brutes neck. The Brute Captain looks at the Arbiter from the corner of his eye. "More will co-" The Arbiter cuts the Captain off by jamming the overheated rifle into his neck and burning away a large amount of flesh.The brute falls to the ground screaming and hemorrhaging from the neck. "You're sick," Johnson stated. "Let them come," The Arbiter said. "I shall burn them all as their chieftain once burned me." Miranda then smacks a startled Brute off the edge of the platform with the hammer. (A/n: How she managed to pick that thing up, we may never know.)
She smacks the blinded Brute off the edge of the platform. 343 hovers over them laughing. "Excellent", he said "now activate the ring"! "No oracle" the Arbiter snaps. 'Oracle, you may be, but I will not kill us." "Allow me to rephrase that. Give it to me!" 343 lunges at the Arbiter's head, causing it to bleed and giving his vision a shade of purple. A humming noise can be heard from above the roof of the control room. About twenty sentinals and six enforcer units come bursting in from the roof.
While the Arbiter is getting up Johnson hollared "get out of here, both of yah, I'll take 'em." He finds his beam rifle and takes aim. Miranda helps the Arbiter up thinking to her self 'he better not betray us later when we could have left him to die.' They rush out through the still burning entrance to the ledge. The Arbiter looks at his Banshee to find it had been reduced to scrap metal by additional sentinals.
The Arbiter lets his eyes linger a moment on the key of destruction before shattering it on the cold metal under his feet, reveling in the fact that it can destroy no more. Johnson backed out of the "door" to the control room to the platform where his allies are waiting. "Dammit!" he yelled, turning to face the Arbiter. "Why do your weapons overheat and burn your friggen hand?" He threw the smoldering hot weapon at a sentinal, causing it to catch fire and crash into an Enforcer, lowering its shield in the process. "Even if we survive this friendly gathering," Johnson begins, with more than a hint of sarcasm. "How do we get down?" Something casted a large shadow over the three warriors.