The concluding scene after taking down the large Covenant AA gun literally encompasses a dread-inducing feeling as any dedicated Halo fan immediately could tell what's happening in the following scene. After the Portal activates, a lone Covenant CCS-Class Battlecruiser is shown appearing from slipspace, strangely letting off a suspicious brown-colored smoke from its midsection. The Arbiter thinks it's merely more regular Covenant troops to deal with, boy is he ever wrong...
Contrasting the previous games, now the Marines (as well as Elites and Brutes) can be "Floodiefied" in realtime. Yes, they transform into Combat Forms before your very eyes, crying out in horror as the parasite tunnels into their chest cavity and takes control. Not to mention that if you manage to shoot an infected soldier in a way that doesn't make it explode and walk up to its body, you can see one clinging to the spine...
Brute Combat Forms are a delightful new breed of horror - Instead of being neatly situated in the chest, as seen with human and sangheili Combat Forms, the Flood in this case◊ rests inside the Brute's throat, grotesquely distending their jaws so it can peek out.
The Flood Pure Forms, made entirely out of Flood biomass. You try to kill one of the spider-like Stalker Forms, but it only ends up almost-instantaneously mutating into another form which tries to relentlessly kill you from afar or at close range.
Perhaps the creepiest parts in the game are when the Flood start talking to you. Hearing the Gravemind cursing and taunting you as his minions swarm you from every direction is chilling.
From the level Floodgate, the insane Marine considering suicide adds to the horrific atmosphere, much like the psychotic Marine in the first game.
Same voice actor for both. That guy is disturbing in-character.
One line that the suicidal Marine said gives a good description of an infected person: "I could see it crawling, SLIDING AROUND BENEATH THEIR SKIN!"
The very circumstances of the mission and its aftermath are horrifying. The quarantine space-blockade around High Charity mentioned in the folder above? A single infested ship managed to slip through it and reach Earth. The town of Voi is overrun in minutes, the glut of bodies from the just-concluded battle of "The Storm" being reanimated left and right. In the end, while the arrival of the Fleet of Retribution helps stem the tide, the only way to prevent a full-on Zombie Apocalypse is to completely obliterate Voi and its surroundings; Miranda suggests overloading the infested spaceship's reactor core, while the Elites opt for Orbital Bombardment.
Rtas 'Vadum: One single Flood spore can destroy a species. Were it not for the Arbiter's counsel, I would have glassed your entire planet!
Really think about that for a moment. The Elites had enough ships in orbit of Earth to validate that threat, if they chose to devote the necessary time to it. Humanity had absolutely no say in the matter, being too weak to oppose their own ally and depending on them for survival. The only, only reason that Earth's biosphere wasn't destroyed that day... was because the Arbiter vouched for us in a conversation. The survival of hundreds of thousands of years of civilization was decided based solely on that exchange; it is literally the case in the Halo universe that if not for the Arbiter convincing the Elites to spare most of the Earth, a significant chunk of the human race would have been exterminated on the will of a single renegade fleet commander who spoke about the matter as if he was deciding what to have for dinner. Puny Earthlings has never been shown more subtly or terrifyingly.
There's only two UNSC officers at the war conference on the Shadow of Intent, one of them being a relatively junior officer. The Doylist explanation is that Bungie wanted to keep the cutscene relatively light and only putting necessary characters in. The Watsonian explanation is that this is all the UNSC has left.
Cortana has been captured and tortured. She has something that the Gravemind wants, and he will take it by force. As an AI, Cortana can't be raped in the traditional sense, but the implications are still very much there.
And here's this fun little message from the Gravemind if you listen to the Flood theme backwards: "Side by side, we march as one. Humans and Elites will die. The Earth will fall if we strike together. So forth shall all life."
Browsing the terminals in the game. Between the lack of noise in many areas you find them in, the odd "swooping" sounds as you interact with them, the random alarm prompts and the oddly incoherent messages based around the apocalypse of the Forerunners and talking about the death of millions in many cases, it all adds together into a Nothing Is Scarier form of creepiness.
"I SEE YOU RECLAIMER." Even more creepier than you realize that the one who sent those words was Mendicant Bias, the Forerunner A.I. who betrayed his masters for the Flood, which caused the first activation of the Halos. The final (Legendary) Terminal is almost heartwarming, though.
Much like the previous games, the soundtrack has a few choice moments:
First, we have Dread Intrusion played during the level Floodgate. It starts off in the typical, already-creepy Flood themes but soon adds back-masked speech from the Gravemind. Play it in reverse, and you get this. The middle segment is an almost-heroic sounding drum but reminiscent of "Ghosts of Reach" from the Halo 2 soundtrack, but when it gets to the pause, instead of returning with doubled-up awesome, you hear a strange wailing screech come in, and it returns to creepy ambiance music.
In the level The Covenant, when the Flood shows up, the song Black Tower is played. Again, a voice is heard. Play it backwards and be treated to this. This appears to be a reference to T.S. Elliot's poem The Hollow Men.
Possibly Gravemind's creepiest line in any game. After Truth dies and Gravemind betrays you, massive tentacles burst up from beneath the platform the Chief and the Arbiter are on. This is then followed by insane, diseased laughter, followed by this:
Gravemind: Now the gate has been unlatched, headstones pushed aside... corpses shift and offer room... a fate you must abide.
His final words to the now Flood-infected Prophet of Truth right before the Arbiter silences him for good is no less chilling:
Arbiter: I will have my revenge. On a Prophet!Not a plague!
Truth: My feet tread the path.....I shall become a God!
Though he had it coming from lightyears away, Truth's infection is still particularly gruesome. Instead of the horrifying but thankfully relatively quick infections by way of Infection Form, Truth is slowly being overtaken by inhaling Flood spores, still conscious and able to speak and (weakly) move. Flood biomass grows from his skin like tumours, and one BURSTS and releases a Flood tentacle that caresses his face! The Gravemind is taking its sweet time with Truth, just because it amuses him.
The level Cortana. There's a reason that's the least-played level.
For those who don't know, this level is the one where you essentially break into the Flood's house in order to rescue Cortana. The "house" was originally a spaceship, but almost every wall, floor, and ceiling is covered in "Flood biomass," which turn out to be oozing, infected pustules that spew enemies when shot. It's kind of like the halls of an insect hive. The Flood will attack from all sides (including up) as you try to navigate this somewhat-nightmarish landscape. It doesn't help that the level is somewhat confusing; many players get turned around easily even after several playthroughs. As you fight through it, you get to listen to Cortana's tortured, disjointed rantings and Gravemind's apocalyptic proclamations. Nearly all of Cortana's transmissions are either outright skin-crawling in their delivery, if not outright terrifying, with some carrying threatening tones in her voice.
What's worse is that as the level progresses, Cortana's transmissions become more and more frantic and confusing, eventually becoming incoherent and horrific screams of pain...before she suddenly starts speaking in a lifeless monotone. Not only that, at that point, her graphics turn from blue to green. Also, the Gravemind moments become more and more "insane evil genocide monster."
"We exist together now. Two corpses in one grave".
A collection of lies, that's all I am! Stolen thoughts and memories!
"Gravemind: (intrigued) "And yet, perhaps a part of her...remains?" (maniacal laughter, fades into Cortana's'' maniacal laughter). Her laughter is really unsettling.
"It was THE COIN'S FAULT! I wanted to KEEP YOU SAFE! Make you STRONG!" Made a thousand times creepier if you've read The Fall of Reach and know the significance of that transmission.
Equal part Tear Jerker and Nightmare Fuel of the Nothing Is Scarier variety, the very last "Cortana moment" you have before rescuing her is just her lying motionless on the floor.
Investigate the crashed pelican early on in the level and you'll hear Cortana talking over the loudspeaker. While not a "real" Cortana moment, what she says is incredibly disturbing: "I ran, tried to stay hidden, but there was no escape! He cornered me, wrapped me tight... and brought me close".
Equal part Awesome and terrifying, when you finally rescue Cortana, the Gravemind has a Villainous Breakdown where it just roars in anger that the Chief has managed to throw a wrench in its plan. That's right, you essentially overcame an Eldritch Abomination and it's pissed off that it failed to stop you on its home turf.
343 Guilty Spark has a complete mental breakdown in the last level, going through rampancy. It's very scary to see such an affable, if slightly annoying, character completely turning 180 and becoming an extremely dangerous foe who has lost his mind. Before it, you don't expect him to be a harmful threat, but then he proves you wrong big time by killing Johnson and burning the Master Chief. When you fight him, nothing works. Grenades, pistol, machineguns, sniper rifles, plasma guns, anti-tank weapons - none of them work. The only thing you can do is make him snap even further, and pretty soon you start feeling your heart pumping from desperation alone. The red eye works, too, for the fear factor.
"Hunted", a live-action piece from the Believe marketing campaign, featuring an old veteran Marine talking about the war long after it happened. The Marines had to go dark and quiet in the woods throughout the night while the Brutes were right next to them, trying to hunt them down. Talk about Nothing Is Scarier.
On the topic of live-action, in the lead-up to Halo 3's release Bungie also released "Landfall", a short live-action sequence showcasing regular UNSC Marines and ODSTs conducting a mission to pinpoint Master Chief's trajectory as he reenters Earth's atmosphere. The short film plays out like a deconstruction of Halo as a whole. This isn't a video game with its Acceptable Breaks from Reality and these are not Spartans, so no Powered Armor and Energy Shields. The action is tense, bleak and desperate and even basic enemy weapons like the Spiker leave gruesome wounds that incapacitate the Marines they hit. From the perspective of regular humans the Brutes are giantKiller Gorillas who snarl like animals instead of talking like in the game. Near misses from plasma weaponry is enough to kill or seriously injure Marines. This really gives a feeling of how bad the Human-Covenant war was from the perspective of average humans. It's no wonder Spartans were essentially huge morale boosters when you consider what it was like for regular soldiers.
◊ rests inside the Brute's throat, grotesquely distending their jaws so it can peek out.
