Headscratchers / Halo 2

• Why did the Heretic Leader shoot at the Arbiter before he could ask the Monitor about Halo? If he wanted him to know the truth, then he would have at least let him talk to the Monitor.
  • Most likely because the Arbiter is acting on the will of the Prophets (who described the role of the Arbiter as the vanguard of the Great Journey) and, at this point in time, hasn't had the revelations that made him second-guess the Covenant religion. See the climax of the game, where the Arbiter essentially takes 'Refumee's role when he confronts Tartarus, and we saw how that went (namely how Tartarus was high as a kite on his faith and refused to believe the truth, even when one of the constructs of the gods he worshipped told him the purpose of the Halo array and the fate of the Forerunners to his face). It's safe to assume that 'Refumee was probably betting on the Arbiter being just as blindly loyal as Tartarus (and therefore impossible to win over, even if 343 Guilty Spark gave him the same answers that he gave Tartarus), and opted to use Spark as a distraction so he could catch the Arbiter by surprise.
• Why would Miranda Keyes abandon her ship to go get the Index? Especially in a place filled with Flood(where she can easily be infected)?
  • Probably a mixture of wanting to follow in her father's legacy, and mounting casualties requiring her direct presence to retrieve a very critical mission objective.
• Truth replaced the Elites with Brutes as the leading force of the Covenant because they failed to protect Regret, yet the Brutes let a single Flood infection form latch onto Mercy and Truth just leaves him to die because "the Great Journey waits for no one". How much time would be lost pulling the infection form off of him?
  • It's a political move to get the Elites out of the way and replace them with the more obedient Brutes, and also get Regret out of the picture.
  • Once the infection form got on him Mercy was dead either way, so there wasn't much point in pulling it off him. And of course, if he was dead as well that was more power for Truth.
  • Removing the Elites was as mentioned above, a political move, especially since Truth and Mercy abandoned Regret in the first place once the Master Chief came looking for him. Even if the infection form hadn't already done some sort of damage or infection to Mercy once it got a hold on him, his death meant Truth was the only remaining Hierarch.
• Why does Miranda Keyes order the Chief to kill Regret? Why not capture him and bring him back to Earth as a high value POW?
  • Likely because there would be no way to secure him against a massive Covenant rescue mission.
  • Earth was being hammered by a hefty Covenant fleet when the In Amber Clad jumped out, so there may have simply been no place to take him. The discovery of the Halo array may have also changed the original "capture a Prophet and force a peace negotiation" mission plan that was about to be launched before Reach fell.
• Why do the Prophets need an Arbiter to deal with the Heretics? Couldn't R'tas and his strike team have done the job?
  • It's implied in the terminals that the Arbiter position became a way to quietly dispose of any Elite who gained the influence to possibly challenge the Prophets. The Heretics were also a convenient way to eliminate two problems - either the Arbiter kills the Heretics, or the Heretics kill the Arbiter (and are probably themselves eliminated in turn by R'tas and his team).
• Truth sends Tartarus to activate the Halo arrays. However, at this point, Truth did not have access to the Forerunner ship that would take him to the Ark, and thus out of range of the arrays. In Halo 3, we learn that he knew what firing the arrays actually did, so what was his plan to not get wiped out by the firing of the arrays?
• How do the UNSC’s weapons work in the exterior parts of the Cairo level, since they take place in a vacuum? Basically all the UNSC weapons that use bullets use gunpowder and cartridges (according to this troper’s knowledge, at least), so shouldn’t they not work at all, since there’s no oxygen to help fuel that reaction (or even ignite the powder in the first place)? This troper recognizes that it’s probably just a gameplay oversight (since it would be a headache to deal with if a player couldn’t use most of the weapons they have access to in those brief portions of the game), but, still, what lore/in-universe reason could explain that?
  • Firearms work just fine in vacuum. The powder contains its own oxidizer.
• How did the Gravemind assimilate the Prophet of Regret? Not only did Master Chief kill him by punching him in the head with the force of getting hit by a truck, but the Covenant fleet started glassing the temple after he died in an attempt to kill Master Chief, which would also certainly have vaporized the Prophet's corpse?