Sierra 117

Sierra 117 is the second campaign level of Halo 3. It is the first level to feature real gameplay, as opposed to the first level, Arrival, which is merely a cutscene and tutorial. Also, take note that this is the First Level that features messages from Cortana on certain occasions.

Upon completing it on the Normal, Heroic, or Legendary difficulties, the player will earn the "Landfall" achievement and 20 Gamerpoints. Upon earning 15,000 points in FFA Metascoring, the player will be awarded with the Guerilla achievement and 10 gamerpoints.

Setting
This level takes place in an African jungle that lies on the southern slopes of Shira peak, as confirmed via the hexadecimal code of the Halo 3 Beta and physically confirmed in the Halo 3 E3 2007 Trailer and the short video subsequent Bungie Podcasts (Mawenzi peak can be seen slightly obscured to the right of Uhuru peak, both which are part of the Kilimanjaro mountain.) The jungle is home to a Covenant Loyalist encampment, and hosts lush verdant forestry, rivers, rocky landscapes, waterfalls, and tunnels. It has been compared to "Off the Rock, Through the Bush, Nothing but Jackal" of Halo 2's Delta Halo, although it isn't the same place, because Sierra 117 is on Earth and Delta Halo is in Installation 05.

Plot
Having been found by Johnson and the Arbiter, the Master Chief is escorted through the jungle. Johnson has with him two squads of marines but after spotting a Covenant Phantom overhead, he decides to split them into two teams to try and reach an evacuation point at the river. The Master Chief, the Arbiter and one squad head one way, following the stream, while Johnson and the other UNSC forces scale a waterfall and head another way.

The Chief encounters the previously patrolling Phantoms, which drop off Brutes and Grunts. They also have to face Carbine-wielding and Sniper Jackals. Around the time they finish mopping up the first group of Covenant, they receive notice from Johnson that they cannot get into contact with another marine team, Bravo. Almost immediately after, the group comes across a stricken Marine held captive by a Brute on a log above them. The Brute beats the Marine, inquiring about an "Ark". After killing the Brute who was torturing the marine, they are told the rest of Bravo is dead, apparently pinned down by a Phantom and killed by a Brute Chieftain. The Bravo team survivor, Gunnery Sergeant Reynolds, then joins their cause.

Further on, UNSC forces and the Arbiter make it to the river for evac, but the Pelicans at the evac point are already under attack by Covenant infantry. Johnson is seen firing from the back of one of the Pelicans with a Machine Gun Turret and with combined fire, the Covenant are momentarily pushed back. However, before the Chief and Arbiter can reach them, Banshees show up and fire on the Pelicans with their Fuel Rod Cannons. Heavily damaged, they make a fiery exit out of the Chief's sight and more Brute and Grunt reinforcements show up to mop up survivors. After pushing through the Covenant forces, the Chief and the Arbiter are told over the COM that Johnson's Pelican has crash landed and shortly afterwards come across him and his squad fleeing from the crash site, pursued by Brutes and Grunts. The Chieftain mentioned earlier pulls his own Phantom out of the fight to regroup.

They desperately try and catch up with Johnson, killing dozens of Grunts, many Brutes and a handful of Carbine Jackals and Jackal Snipers that were crowded around the area. After coming across the crashed Pelican, they find Sniper Rifles and Battle Rifles and they discover over the Pelican's radio that there is no sign of the second Pelican. It is assumed to have crashed and sunk into the lake. Master Chief, Arbiter and the surviving marines then find themselves in a thick jungle and have to fight past Jackals hiding in the trees and on the ground, with no sign of Johnson or his squad of marines.

They then reach a large dam where they see Johnson being taunted and kicked into a small building and held captive by a Brute Chieftain. It is implied this is the same Chieftain that killed Bravo's men and pursued Johnson from his crash site. The area is also littered with Grunts and Jackals as well as half a dozen Brutes. With slow progress, the two heroes manage to fight their way through and around the dam and eventually take down the Brute Chieftain. They then rescue Johnson and the three surviving marines from his squad.

Johnson calls in Pelican Kilo 023 piloted by Hocus to come and pick them up, but are first engaged by two Phantoms which drop off hordes of Grunts and a few Brute Captains wielding Brute Shots. Whilst the group engages and kills the ground forces, the Pelican arrives and takes down the two Phantoms with missiles. Hocus then lands and evacuates the survivors and Johnson is seen patting the Chief on the shoulder in thanks before the Pelican flies off.

Walk It Off
{Gameplay}


 * Johnson: "First Squad, you're my scouts. Move out! Quiet as you can."

-(Co-op change) Johnson: "First Squad, you're my scouts. Arbiter, watch the Chief's back. Move out! Quiet as you can."

{If you wait and hang around}

Johnson: "Let's get moving, Chief. Come on. I'll lead you out."


 * Johnson: "Bravo Team, this is Johnson. We got him. Fall back to the extraction point. Over."


 * Reynolds (COM): "Roger that. Reynolds out."

Brute howls off in the distance.


 * Marine #1: "That sounded close."


 * Marine #2: "Yeah, too close."


 * Reynolds (COM): "Johnson, you be advised. Hostiles are (static) on the move (static). I've got eyes on a (static) Brute Pack (static). Over."

There is the ominous whisper of gravitational drives as a Phantom flies overhead above the trees.
 * Johnson: "Say again, Gunny. You're breaking up."


 * Marine #2 (Whisper): "Sergeant Major, Phantom inbound."


 * Johnson (Whisper) :"We stick together, we're gonna get spotted. We'll split up, and meet back at the LZ. Chief, go with the Arbiter, head toward the river. Second Squad, you're with me."

-(Co-op change) Johnson : "Chief. You and the Arbiter head toward the river."

''Johnson and Second Squad climb up the cliff by the water fall. The Chief and Arbiter lead First Squad. The Arbiter leads the Chief up on some rocks around a pile of fallen logs, while First Squad waits to go straight over, pointing out a Brute Captain Major.''


 * Brute Captain: "Spread out, you whelps! Find them!"


 * Marine #1 (Whisper): "Up ahead! Single Brute, plus backup!"
 * Marine #2: "He's got power armour chief,"

''First Squad engages the Brute and his Grunt subordinates along with the Master Chief and the Arbiter, taking them by surprise. They regroup.''


 * Arbiter (to Brute corpse): "The Prophets are liars, but you are fools to do their bidding!"

''Two Phantoms draw near, each deploying a Brute and a squad of Grunts, blocking the advance of the Master Chief and his allies. Eventually, they are cleared, and the Marines form up at a winking flare at an underground cave.''


 * Marine #2 or Female Marine #1: "Those Brutes are tough. Grunts ain't no slouches either."


 * Arbiter: "The Grunt's new-found courage is but fear. When we are victorious, all who serve the Prophets will be punished."

-(Reply in Co-op) Female Marine #1 or Marine #1: "Maybe the Brutes put something in their tanks."

''After advancing through the caves, a massive forested expanse is found: the "Grunt Camp". Sleeping Grunts litter the first half while a few Brutes, Jackals, and Grunts patrol the far hills.''


 * Marine #1 or #2: "Sleepers! Take 'em out, nice and quiet! {On Heroic and Legendary} Jackals, on the ridge! Stay low; looks like they've got Carbines."

{After clearing the Grunt Camp}


 * Johnson (COM): "Pelicans are en route, Chief, but I can't reach Bravo. If you find 'em, get 'em to the extraction point."

Beyond the encampment, a Brute Captain is torturing a Marine Sergeant on a log {It is possible and optional to save the Marine by killing the Brute}.


 * Brute Captain: "Tell me its location!"

{If Reynolds is not saved}
 * Reynolds: "Kiss...my...ass."

The Brute Captain breaks Reynolds spine and throws him down, noticing the Master Chief and Arbiter.

{If Reynolds is saved}

Reynolds jumps down from the log, grabbing a nearby fallen Assault Rifle and joining the Master Chief and the Arbiter in their fight


 * Reynolds: "Brute Chieftain and a Phantom. They pinned us down...killed my men."

First Squad continues on until they reach another cave.


 * Arbiter: "The river. Hurry!"

''The UNSC force continues forward, towards further caves and pushing towards the river, where Johnson has established an extraction point for Second Squad. They head down a steep slope for some underground caves that lead to the river.''


 * Cortana (Cortana Moment): "Could you sacrifice me to complete your mission? Could you watch me die?"


 * Marine #3: "Sir, you okay?"


 * Marine #4: "Your vitals just pinged KIA."

Charlie Foxtrot
''Second Squad leaves the caves; the river is around the next bend. Three Marine corpses are scattered on the ground, with BR55HB SR Battle Rifle ammunition and Fragmentation Grenades.''


 * Johnson (COM): "Chief, Pelicans are at the river. We've got company, so hustle up!"


 * Arbiter: "Grenades! Blow them to bits!"

''Beyond the steep slope is a river substation, next to a raging river. A pair of Pelican Dropships, hover above the river, and their door gunners fire on a cluster of Covenant troops that have tunneled themselves in the substation. They are the extraction force to evacuate the Master Chief and his team.''


 * Female Pelican Pilot (COM): "Hold on. Got a contact."

As the Master Chief and his men wind nearer to the Pelicans in the substation, two Banshees streak in along the river.


 * Female Pelican Pilot (COM): "Banshees! Fast approach!!"


 * Echo 51 (COM): "Break off-now!"

The Banshees launch a high-speed strafing run against the Pelicans, and explosions cascade over them as the Pelicans rock.


 * Echo 51 (COM): "Watch yourself!"


 * Female Pelican Pilot (COM): "I'm hit! I'm hit! AAAHHHH!"


 * Echo 51 (COM): "Lost a thruster. Hang on!"


 * Johnson (COM): "Get a hold of her!


 * Echo 51 (COM): "Negative! We're going down!"

''Both Pelicans streak away around the river bend. The unidentified Pelican plunges into the river beyond the dam, but Echo 51 loses control, plowing into the top of the cliff and drops down. While Master Chief, the Arbiter, and the Marines fight through to secure the substation despite two waves of Brute-led Covenant Loyalist reinforcements, Johnson and his team leave the wreck of Echo 51 but are beset by a Brute ambush .''


 * Arbiter (A Marine in co-op): "The Banshees will return. Back into the jungle, hurry."


 * Johnson (COM): "Chief, can you hear me..(static). My bird's down. Half a click..(static)..from your position."

{If on Easy or Normal}
 * Marine #1 or #2: "Jackals. On the ridge. Stay low. Looks like they got Carbines."

''After the Chief and Arbiter pass through the short Jackal Sniper-laden gorge "Sniper Alley", they see a bridge. Three Marines are crossing it, under heavy fire, retreating from Echo 51's crashed Pelican. They hear a familiar voice over the COM unit as a Brute leads a charge against the fleeing Marines.''


 * Johnson (COM): "Come on, you dumb apes! You want breakfast? You gotta catch it!"

Johnson and the Marines frag the Brute and his fellow soldiers on the bridge, and run off into a cave.

''The Chief and Arbiter encounter many hostiles, including a Brute Chieftain on the side of a Phantom, who flies off when either his gunner, or much of his troops are eliminated. The Chief and Arbiter secure the area, and discover Echo 51's crash site by the riverside: the Pelican flipped over after hitting the cliff, scattering ammunition and weapon racks in the area, including a SRS99D-S2 AM Sniper Rifle and other munitions. Echo 51's radio is still operational, however.''

{If you wait by Echo 51's radio}


 * Crow's Nest Controller (Echo 51's Radio): "Echo Five-One, this is Crow's Nest. Echo Five-One, please respond!

(Pause)


 * Crow's Nest Controller (Echo 51's Radio): Hocus, Five-One is down, divert for emergency evac. Over."

{If any of Echo 51's Marines are still alive}


 * Arbiter: "Again, the Brutes show their weakness."

{If any Marines accompany}
 * Marine #3 or #4: "Sergeant Major went this way, Chief. Through the cave."

The Master Chief leads the Arbiter (and any accompanying Marines) through the caves towards where Johnson is being held.

Quid Pro Quo
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{Cutscene}

''At the end, the Master Chief and Arbiter reach a low cliff, viewing a Loyalist-held dam. The Arbiter spots the Chieftain beating Johnson on the far left in front of a small building''


 * Arbiter: "See how they bait their trap?"

''The Chieftain roars at Johnson. Johnson punches back with no effect.''


 * Arbiter: "I will help you spring it."

''The Chieftain growls loudly and kicks him back inside the "prison".

{Gameplay}

''The Chief and Arbiter battle their way across the dam, taking down the Chieftain. They finally reach Johnson, who's been tied up and imprisoned behind a Plasma Shield.''


 * Johnson: "This isn't as fun as it looks. Cut the power!"

(If no Marines came with you or died, the other three Marines in the prison will be still alive and await rescue)


 * Marine Escapee #1: "Brutes were gonna gut us, sir."

The Master Chief releases the plasma shield that was imprisoning Johnson and his fellow Marines.


 * Johnson: "We're even, as long as we're only counting today. Kilo 23, what's your ETA?"


 * Hocus (COM): "Imminent, Sergeant. Find some cover. Gotta clear a path."

Johnson and the Marines grab Covenant weaponry from nearby crates.


 * Johnson: "Roger that, Hocus. Friendly gunship, coming in hot!"

''Two Phantoms arrive, carrying reinforcements. The Chief, Arbiter, Johnson and any accompanying Marines hold position until Kilo 23 arrives.''


 * Johnson: "Hocus! Phantom!"


 * Hocus (COM): "I see 'em! Standby. Going loud. Everyone down!"

''The Pelican Dropship Kilo 23 rounds the river bend, directly in front of the two hovering Phantoms. Hocus, Kilo 23's pilot, lets loose a rocket barrage, etching the air with vapor contrails as the first Phantom explodes in a brilliant coruscation of light.''


 * Hocus (COM): "Scratch one Phantom!"

{If any ground forces remain, Kilo 23 will take them out.} Kilo 23 fires two rocket barrages at the second Phantom, and sends it plunging into the river.


 * Hocus (COM): "Scratch two!"

''Hocus lowers the Pelican to the dam for pickup. Johnson, the Master Chief, the Arbiter and any remaining Marines board Kilo 23.''


 * Johnson: (If you don't board the Pelican) Come on Chief! The world won't save itself!

(If you still don't board)


 * Johnson: "Are you or are you not going to finish the fight?"

(Sometimes if you kill all surviving marines now as well as the Arbiter, Hocus will take off and fire missiles at you

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{Cutscene}

''Kilo 23 takes off. Johnson gives the Chief a pat on the shoulder and goes into the cockpit. Kilo 23 shuts the back hatch and flies over the first dam, en route to Crow's Nest.''

Sentries on watch in the jungle spots Kilo 23 on approach.


 * Marine Sentry: "IFF confirmed. Contact is Pelican Dropship Kilo 23. Over."


 * Crow's Nest Controller #2 (COM): "Roger that. What's the word, Kilo 23?"


 * Hocus (COM): "Sierra 117 onboard. Request priority clearance. Over."

The two marine Sentries bump their fists and smile.


 * Crow's Nest Controller #2 (COM): "Deck's yours. Come on down."

Kilo 23 proceeds to land in a hole in the ground.

Part 1: Walk It Off
From the level's beginning, there really is only one way to go. It's a very linear space, and you shouldn't have any trouble following it. When the Phantom flies overhead, you should see a high rock on the right, just the right height to be jumped up to. Unfortunately, on Legendary you have a pretty useless weapon set, so just use the Pistol to open fire on the gold-armored Captain-Major Brute. As soon as the clip is empty, get in motion. About five or six Grunts will show up from the left end of the log in pretty rapid succession. Headshot them and then finish off the Brute, if you need to. (Often, the Marines will have finished him by this point, or at least softened him up a little). Once that group is dead, dual-wield a plasma pistol with your magnum and move forward until you hear the sound of a Phantom inbound. Quick, back up and take cover behind the log, or the Phantom will make you bleed for it. As soon as it departs, move forward again. The Phantom dropped what will be referred to henceforth as a lance, or a Brute leading about four or five Grunts. Kill the Brute first. At this range, he should be easy to noob-combo, being that he's unaware of your presence. The Grunts will probably panic, but some may not, so drop the PP and keep the magnum ready. Once everything there is dead, drop the pistol in favor of a Brute Shot. There probably won't be much ammo in it, but that doesn't matter yet. For the time being, just head left, through the foliage, and down onto a rock to claim the Blind Skull. Even if you've already gotten it, it can be an invaluable weapon here due to the massive melee damage. Once you've got it, get back up onto solid ground and head across the river towards the two Lances nearby. One is further forward, with Grunts on the sides and a Brute-Shot Brute on a rock. You can run in and make him hurt with the skull (my favorite) or attempt to noob-combo him. (The NC is always a safe, if cheap, bet, and you should use it when nothing else seems to work). The second lance is further away, with three Grunts and a Brute-Shot Brute who likes to hide behind trees. Watch out for him. Once they're all dead, drop the skull. Fill up on Brute Shot ammo and then progress on through the caves. Shortly, you will arrive at the second main encounter of the level.

This encounter takes the form of a large, nonlinear valley, containing about fifteen Grunts (about half are asleep), five regular Jackals, three carbine Jackals, and five or six Brutes. This isn't an easy battle, but it shouldn't be impossible to manage. Some things to prepare: swap out the MA5C for a Carbine. Then, quickly move downhill and from tree to tree, killing sleeping Grunts. This will massively reduce the amount of incoming fire in the battle to come. Then, start by waiting for a small group of enemies to approach the clutch of plasma batteries on the far left side of the area, and carbine them for a multikill. So it begins.

The three snipers, being the longest-range foes, are your highest priority. One is quite close, on a rock one level down from the place where you entered the area—right below the Arbiter. In fact, the Arbiter may already have killed him. The two others are harder to find, hidden in the foliage on the ridge up at the top right side of the area. Pinpoint them by their shots, then zoom in and carbine-spam. (You have an infinite amount of carbine ammo in this area, so no need to hesitate). Once all three are dead, it's time to head down onto the valley floor. Fight your way across the river, taking care to look both ways for enemies as you cross. If you have picked up a Bubble Shield by now, I'd suggest that you deploy it on one of the raised areas just across the river to establish a beachhead. Target Brutes first, then Needler Grunts, then Jackals, then regular Grunts. With the Brutes, you may want to use the Brute Shot melee to knock off their armor before you go for the headshot. By the time you've cleared the far bank of the river, you should have reduced the enemy forces to a single Lance. Swap out the Brute Shot for a Needler and use it to kill the Brute. Mop up the stragglers with Carbine fire. Once you've filled up on ammo again, move on down the path.

Up on the log above, Sergeant Reynolds is being menaced by a Brute. Needle the Brute, then start moving forward under the log to get up the slope. There's a Carbine Jackal and a Grunt or two here, so be sure to kill them before moving on. Past this area is a section off to the left, out of which a few Grunts will come when you get near. Kill them and go into the place they came from. You can choose here to pick up the new, slightly better BR, or keep your carbine. I prefer the carbine, so I'll mention it in this walkthrough, but you can use the BR in its place if you please. At the far end of this area is a pair of Jackals (without Carbines, thankfully) and a rather sneaky Lance who I always get ambushed by. Again, use the Needler on the Brute and the Carbine on the Grunts. Follow the tunnel past the Cortana moment and you've completed this section.

Part 2: Charlie Foxtrot
To the left, right after you exit the tunnel, is a dead Marine with a BR and some grenades. Take them as needed and then head down the path until you find yourself overlooking a large area by the river. On the right is a dead guy who had a whole mess of frag grenades: five, I think. Lob them one after another into the Covenant below. Once you've done so, jump down from the ledge and take a left to find another frag grenade cache to chuck at your foes. Although there are two Lances in the valley when you arrive, it's hard to say exactly how many will leave when the Phantom arrives. Usually, at least the Brutes walk away. But they're not your chief worry. Across the stream are two Jackal snipers, and these guys have actual beam rifles of one-hit-killness. Use extreme caution and terminate at range. Once they're dead and the Phantom has left, you're free to begin the second and most difficult phase of this battle: attacking the dam.

This part can be obscenely difficult on Legendary, not simply because of numbers (though you will be vastly outnumbered) nor because of firepower (although you will be likewise outgunned) but because you tend to get nasty checkpoints. There are two ways to get up onto the dam: just jumping straight up from below (nearly suicidal but not impossible) or walking up the left path (slow but safer). If you want to jump right up, then go ahead and do it. I'd recommend moving a lot, throwing grenades a lot, dropping Bubble Shields a lot, and watching your back obsessively. If you choose the left path, then beware of the four Jackals (two normal and two carbine) on the path itself, as well as the lurking carbine Jackal up on a ledge to the left.

---

You should have picked up a Bubble shield somewhere along the line. Deploy it in this next area if under heavy fire. Once you're out of "sniper alley", you will come across Johnson's crashed Pelican, and a massive horde of Covenant Loyalist resistance. Pick up the Battle Rifle and Sniper Rifle at the crashed Pelican site before moving forward to the last section of Sierra-117. You do not need the Sniper Rifle here, but it is strongly suggested to grab it, as it will make taking out the Jackal Snipers and Brutes a lot easier.

Part 3: Quid Pro Quo
After the small letterbox scene where you see Johnson getting beat up by a Brute Chieftain, you can get back to work killing the Covenant Loyalists. You should have the Sniper Rifle, and a Battle Rifle. Immediately switch to your BR and plug the Sniper Jackal down in front of you. Switch back to your SR, stay down, and wait until you can draw a bead on the rest of the snipers (there are about 5 of them). Once they are dead, aim at the Brutes (head shots) and plug them.

You might not be able to kill the Chieftain with sniper fire, so be prepared for a long and drawn out close combat fight with him. However, it is possible to kill him by long distance sniping or BR fire (just wait until his invincibility runs out) It is also possible to stick the Chieftan, but only if you're very lucky. Plasma grenades do not adhere to a Chieftain, so the only way to stick him is to land it on the Hammer he wields. Lay down a pattern of Sniper fire until most of the Grunts, Jackals, and Brutes are gone, then jump on down, switch to your Battle Rifle, and move in. Your SR may be low on ammo, so exchange it for a Needler or Brute Shot.

About the Chieftain: if you see him charging at you and he's glowing white, that means he has his personal invincibility shield on and is preparing to make you a stat in the record book, so be prepared to run. Don't waste ammo or grenades on him when he has this shield activated, you won't do any damage. The best solution is to run around, or get to a high spot to avoid his Hammer and blast radius. A good solution (when the shield is down) is to lob some grenades at him while he's charging and follow up with some automatic fire. The Brute shot is another weapon that is very effective, but never try to melee a Brute Chieftain! The Needler can also be particularly effective, but sometimes the needles bounce off his armor. Anyway, if you forgot to get the SR, use the BR to take out the Jackal Snipers, one by one. as for the other brutes, if you have enough ammo left in your BR, you can use it to shoot them in the head, or else work together with Arbiter to kill them all, after killing the Chieftian. Beat down any Grunts that get in your way.

Upon rescuing Johnson from the makeshift prison the Brutes made, you will have one final engagement. Two Phantoms will arrive dropping a number of Brutes and Grunts. Engage them on the bridge and kill all of them to initiate Pelican Kilo 023 to fire upon the Phantoms destroying them easily. Hop aboard the Pelican to complete the level and begin the cinematic.

Trivia

 * The mutiplayer map Ghost Town is based on Sierra 117, and it is also in the same area.
 * Note that the level is called Sierra 117; Sierra is the word used in the NATO phonetic alphabet to represent the letter S, which, when used in a military sense, generally stands for "sniper." However, in Halo 3, it is S 117 which corresponds to SPARTAN-117. This has been confirmed in the second Bungie Podcast.
 * In the August 2007 EGM Halo 3 Story, Sierra 117 was mistakenly said to be the fifth level in the Halo 3 Campaign.
 * Jumping into the deep water at the point where the pelicans are shot won't kill you or even lower your shields. Also you can see fish swimming and even kill them. (These are what the small yellow dots are on your motion tracker)
 * If you go into the water where the pelicans were shot down, and if you walk into the waterfall, look behind you, and if you position yourself just right, the water will dissappear. (This has been known as the flying fish glitch)
 * Some of the more noteworthy weapons that can be acquired in this level include an Energy Sword (which can be acquired if the Arbiter falls in combat, however it will always have incredibly low energy left), a Machine Gun Turret (located at the dam where your team is accosted by a group of Phantoms), a Sniper Rifle (located at Echo 51s crash site), and a Gravity Hammer (acquired near the end of the level from a Brute Chieftain).
 * Quid pro quo is Latin for "something for something".
 * After Johnson is shot down, when you get to Jackals with carbines if you climb up to where the Jackal on the left rockface in a small corner is a family of cavemen with one carrying a teddy bear.
 * The Achievement "Landfall" is the same name as the Halo Shorts Series, Halo:Landfall.
 * The level is home to two skulls. The Blind skull can be found on a ledge hanging over the precipice following the second encounter of the level. The Iron skull is found on the ledge above the area where Johnson is imprisoned toward the end of the level. When the Iron skull is picked up, the Achievement "Iron" is earned along with 5 gamerscore.
 * The level contains several easter eggs. These include a small group of Cavemen and trees with initials carved into them.
 * The river in the area is the Nkuu river or one of its tributaries, where the Blind skull can be found, is located inside of the Repulic of Tanzania's borders.
 * The compass on the assault rifle is inaccurate - it is out by roughly 90 degrees. Using the compass alone, one would estimate their position as being ontop of Shira peak which is of course to the West of Kibo peak. If you scan the horizon, then you would see Shira peak to the left of Kibo peak.
 * Master Chief didn't come down from the sky in his armor alone. Right at the beginning of the game, a huge chunk of Forerunner ship, the Dreadnought, metal or alloy of what appears to be a balcony, intact with bracing on the underside, is the makeshift heat-shield used by Master Chief.
 * Reynolds will grab an Assault Rifle even if you take it first. The same goes for the Needler Johnson grabs.
 * Johnson grabs a Needler when you rescue him; this could be a reference to the level Truth and Reconciliation, where Captain Keyes grabs a Needler when you free him.
 * It is possible to get spike grenades in this level. Have the catch skull on, and kill a brute. However, it is Extremely rare.
 * The waterfall in the beginning may have been inspired by | Dark Hollow Falls, near Skyline Drive, Virginia.
 * When you reach the cutscene of Quid Pro Quo, you can actually skip the cutscene while the Chieftan is still attacking Johnson. You can snipe the Chieftain then, and he can't do anything about it because of his scripted motions. This is the easiest way to kill him on higher difficulties, namely Heroic and Legendary.
 * At the area where the Pelicans are attacked, an additional Jackal sniper (armed with a Beam Rifle) will spawn if the player takes too long to get through the area. This only occurs on Heroic or Legendary difficuly.

External
-A leaked video from E3 2007.