Editing Sacred Icon

{{Status|Gameplay}}
{{Center|'''Sacred Icon''' redirects here. For the Forerunner artifact, see [[Activation Index]]. For the achievement, see [[Sacred Icon (achievement)]].}}
{{Level infobox
|pagegamelabel=H2
|prev=''[[Regret (Halo 2 level)|Regret]]''
|next=''[[Quarantine Zone]]''
|name='''''Sacred Icon'''''
|image=[[File:H2A SacredIcon Loadscreen.png|300px]]
|game=''[[Halo 2]]'' (<small>''[[Halo 2: Anniversary|Anniversary]]''</small>)
|devname=<code>06a_sentinelwalls</code>{{Ref/File|Id=H2EK|H2EK|H2EK\tags\scenarios\solo\06a_sentinelwalls\06a_sentinelwalls.scenario}}
|player=[[Arbiter_(player_character)#Halo_2|Arbiter]]
|date=[[2552|November 3, 2552]]
|place=[[Sentinel Wall]], [[Installation 05]]
|objective=Lower the [[Containment Shield]], then escape the [[Flood]]-infested wall and rendezvous with Covenant allies in the encampment.
|partime=00:15:00 {{C|''Master Chief Collection''}}
|parscore=7,000 {{C|''Master Chief Collection''}}
}}
{{Article quote|Succeed where others have failed. Lower the shield protecting the Sacred Icon.'''}}
'''Sacred Icon''' is the tenth [[campaign]] level of ''[[Halo 2]]''. As [[Arbiter]] [[Thel 'Vadamee]], the player makes their way through [[Sentinel Wall|a wall]] filled with [[Sentinels]] and [[Flood]], ending in an open-air [[Sangheili]] [[Quarantine Zone|encampment]]. The player must defend it successfully from the Flood onslaught before the next level [[Quarantine Zone (Level)|Quarantine Zone]] starts. This is the first and only level where [[Kig-Yar]] are encountered as allies. This is also one of three levels with human enemies ever in the whole series.

==Transcript==
[https://youtu.be/IPOek0OZGgE '''{''Cutscene''}''']
[http://www.youtube.com/watch?v=jg2doq0dz38'''{''Anniversary Cutscene''}''']

''Fade in on the interior of a [[Covenant]] structure.''

'''[[Sanctum of the Hierarchs]], Covenant Holy City, [[High Charity]]'''

''Panning down, in a large hallway with rows of [[Sangheili Honor Guardsman|Sangheili Honor Guardsmen]]. The [[Arbiter]], [[Thel 'Vadam]]ee, walks through.''

'''Vadamee watches as the [[Jiralhanae]] take Honor Guard equipment from the [[Sangheili]] guards. Some Jiralhanae fight each other for choice parts. As 'Vadamee ascends the stairs leading to the Prophet's Inner Sanctum, a pair of former Honor Guardsmen Sangheili pass by him, without their helmets and [[energy stave]]s. 'Vadamee walks through a large doorway, past the new [[Jiralhanae Honor Guardsman|Jiralhanae Honor Guardsmen]] (one of whom snarls at him in the Anniversary) to where the Prophets of [[Prophet of Truth|Truth]] and [[Prophet of Mercy|Mercy]] speak with [[Rtas 'Vadum]]ee and two of his [[Special Operations Sangheili]].''

[[File:H2A - Changing of the Guard.jpg|300px|thumb|The Jiralhanae strip the Sangheili of their role as Honor Guards for themselves as the Arbiter goes before the High Prophets.]]

*'''Rtas 'Vadumee''': "This is unprecedented... Unacceptable."

*'''Prophet of Truth''': "[[Prophet of Regret|A Hierarch]] is dead, [[Special Operations Commander|Commander]]."

*'''Rtas 'Vadumee''': "His [[John-117|murderer]] was within our grasp. If you had not withdrawn our [[Kez'katu-pattern Phantom|Phantoms]]-"

*'''Prophet of Truth''': ''(slightly indignantly)'' "Are you questioning my decision?"

*'''Rtas 'Vadumee''': "No, Holy One! I only wish to express my concern that the Brutes-"

''The Prophet of Truth holds up a hand for silence.''

*'''Prophet of Truth''': "Re-commissioning the guard was a radical step. But recent events have made it abundantly clear that the Elites can no longer guarantee our safety."

*'''Rtas 'Vadumee''': "I shall relay your... decision, to the Council."

''Rtas 'Vadumee and his Sangheili leave. He nods to 'Vadamee, who returns the nod. The Prophet of Truth speaks to 'Vadamee.''

*'''Prophet of Truth''': "Politics ''(small sigh)''... How tiresome. Do you know, Arbiter, the Elites have threatened to resign? To quit the [[High Council]]? Because of this... [[Changing of the Guard|exchange of hats]]?"

*'''Thel 'Vadamee''': "''We'' have always been your protectors."

*'''Prophet of Truth''': "These are trying times, for all of us."

*'''Prophet of Mercy''': "Even as the [[Fall of Reach|humans' annihilation]] filled us with satisfaction, the [[Battle of Installation 04|loss]] of [[Installation 04|one]] of the [[Halo Array|Sacred Rings]] wracked our hearts with grief."

*'''Prophet of Truth''': "Putting aside our sorrow, we renewed our faith in the prophecy that other rings would be found. And see ''how'' our faith has been rewarded."

''They turn to a large view screen of [[Installation 05]].''

*'''Prophet of Mercy''': "Halo! Its divine wind will rush through the stars, propelling all who are worthy along the [[Great Journey|path to salvation]]."

*'''Prophet of Truth''': "But how to start this process? For ages, we searched for one who might unlock the secrets of the ring. An Oracle. And with your help, we found it."

''They turn toward [[343 Guilty Spark]], who seems to have been suspended in a gravity beam.''

*'''Prophet of Mercy''': "With appropriate humility, we plied the Oracle with questions. And it, with clarity and grace, has shown us... the key."

''Mercy triggers a hologram of the [[Activation index]].''

*'''Prophet of Truth''': "You will journey to the surface of the ring, and retrieve this [[Index|Sacred Icon]]. With it, we shall fulfill our promise."

*'''Prophet of Mercy''': "Salvation for all!"

*'''Prophet of Truth''': "And begin the Great Journey."

[[File:H2A - Spark with Hierarchs and Arbiter.jpg|thumb|300px|Truth and Mercy task the Arbiter with the recovery of the Sacred Icon after conversing with the "Oracle".]]

''Fade to black, fade in on Installation 05. A Phantom flies toward the surface. Cuts to Phantom cockpit: Tartarus approaches from behind the Jiralhanae pilot.''

*'''Tartarus''': "Once the shield is down, we will head straight to the [[Library]]. I do not wish to keep the Hierarchs waiting."

''Focus on 'Vadamee, zoom in as he speaks.''

*'''Thel 'Vadamee''': "The human that killed the Prophet of Regret... Who was it?"

*'''Tartarus''': "Who do you think?"

*'''Thel 'Vadamee''': ''(surprised)'' "The [[John-117|Demon]] is here!?"

''Cut to [[Tartarus]].''

*'''Tartarus''': ''(affirmative snort)'' "Why?" 

''Cut to 'Vadamee, who stands next to a Jiralhanae.''

*'''Tartarus (COM)''': '"Looking for a little payback?"

'''Vadamee draws a [[Vostu-pattern carbine|carbine]] and readies it.''

*'''Thel 'Vadamee''': "Retrieving the Icon is my only concern."

*'''Tartarus (COM)''': ''(skeptical laugh)'' "Of course."

''Cut to exterior panoramic view of Delta Halo's Library, with the [[Sentinel Wall]] in the foreground. The Phantom flies towards the Sentinel Wall and stops over a landing platform. A battle has been fought here recently, as evidenced by [[Aggressor Sentinel]] wreckage and Covenant bodies and blood on the ground.''

[[File:H2A - Enforcer.jpg|thumb|300px|A Sentinel Enforcer closes in on Thel 'Vadamee at the Library's outer perimeter.]]

'''Vadamee drops from the Phantom, which then flies off. Behind 'Vadamee, an [[Enforcer]] rises up and slowly advances. 'Vadamee whirls around and fires three shots (seven in the Anniversary) from his Carbine, to little effect. Suddenly, the Enforcer is hit by a sustained burst of plasma fire and loses its right-back leg. The Phantom flies by, and the Enforcer chases after it.''

*'''Tartarus (COM)''': "Lower the shield, Arbiter! I'll pick you up when you're finished."

'''{''Gameplay''}'''

===Uncomfortable Silence===
''In the first room, there are some [[Constructor]]s repairing an entrance. If 'Vadamee destroys one, some [[Aggressor Sentinel]]s will appear (if on Legendary difficulty, the Sentinels will appear automatically) and will only stop spawning if 'Vadamee destroys the [[Sentinel emitter]]s that create them. He meets a frightened [[Unggoy]] [[Unggoy Major|Major]], who recovers upon seeing the Arbiter''

''After 'Vadamee jumps into the passageways moving downward, and the first room, he meets another Unggoy.''

''After fighting his way through a corridor lined with Sentinel emitters and the dead bodies of Covenant troops, including Jiralhanae, 'Vadamee drops down a [[piston]] into a more open room. He finds a group of Unggoy and [[Kig-Yar]] fighting Sentinels. After he defeats the Sentinels and cuts off any more from entering, one of the Unggoy speak to him.''

*'''Unggoy #1''': "Arbiter... our savior!" ''(pause)'' "Stupid Jackal, say thank you!"

----
''If 'Vadamee stares at the Unggoy long enough, or just waits around:''

*'''Unggoy #1''': "If hungry, eat Jackal!"
----

'''Vadamee moves across a bridge to the next room. A constant stream of Constructors can be seen below the bridge passing through a conduit.''

*'''Tartarus (COM)''': "You're getting close to one of the shield generators. Many of my Brutes have fallen attempting to take it down. Let's see if you fare better."

'''Vadamee finds another piston and enters the tunnel, sending him downwards. An terrified Unggoy runs toward him.''

*'''Unggoy #2''': "[[Enforcer|Big, scary thing]]! Run away! Please! Don't make me go back!"

''Several Sentinel emitters open up, producing more Sentinels.''

*'''Unggoy #2''': "Ahh, more bad things! Arbiter! Protect, protect!"

'''Vadamee reaches another piston, and drops down to the shield generator.''
[[File:H2 SacredIcon ReleaseChamber.jpg|250px|thumb|The chamber with the power source controls.]]
*'''Tartarus (COM)''': "You've reached the power source, Arbiter."

''An Enforcer descends from above.''

*'''Tartarus (COM)''': "It is useless to attack the Enforcer at the front, especially when its shields are up. Stay in the shadows, wait until it loses interest, then strike the beast when its back is turned."

'''Vadamee destroys the Enforcer.''

*'''Tartarus (COM)''': "You've reached the power source. Overload the locks holding it in place."

''After 'Vadamee overloads (or pushes them to save ammo) the first three [[plug lock]]s''

*'''Tartarus (COM)''': "One more, Arbiter."

''Note:  On higher difficulties, the dormant Sentinel emitters in the room will activate and start spawning Sentinels.''

'''Vadamee overloads the last one.''

*'''Tartarus (COM)''': "Release the power source. Now, find a way to remove it from its cradle."

'''Vadamee activates the holo-panel. The Sentinel emitters in the room all explode. The platform drops down and starts moving as the door in front of him opens.''

===Buyer's Remorse===
''Above, the bright-green shield surrounding the Library is fading away, followed by Tartarus's Phantom flying lower towards the other side of the wall.''

*'''Tartarus (COM)''': "Our path to the Library's clear. I'll pick you up on the ledge ahead."

''The door of the approaching wall opens to another Enforcer, which begins to fire on the Phantom.''

*'''Tartarus (COM)''': ''(growls)'' "Blasted machines! Make your own way through the wall, Arbiter!"

''The Phantom retreats, followed by an attack by Aggressor Sentinels and a break-out of [[Flood combat form]]s.''

[[File:MTCC-H2A Marines Fight.jpg|thumb|300px|Marines fighting the Flood in the Sentinel wall.]]
''Eventually clearing the area of hostiles, 'Vadamee jumps through the wide-opened door that several Sentinels used to enter the area. Fighting his way through Flood forms and Sentinels, 'Vadamee reaches a piston at the other end. After clearing another corridor of Flood and surviving an ambush of [[Pod infector]]s, he reaches another piston.''

''As 'Vadamee proceeds through the hallway below, his COM link picks up a UNSC transmission.''

*'''[[Gunnery Sergeant]] [[Marcus Stacker]] (COM)''': "Proceed to the objective, we'll hold out as long as we can! ''(screams painfully)'' Get it off me!"

*'''[[Banks|Staff Sergeant Banks]] (COM)''': "Suppressive fire, suppressive fire!"

'''Vadamee looks across a chasm to see a squad of Marines surrounded by Flood.  The parasites usually overwhelm and kill the outnumbered Marines.  If any Marines do survive, they will fire upon 'Vadamee and any Sentinels present. Fighting his way through twisting hallways full of Flood combat forms, with occasional Sentinels and [[Flood carrier form|carrier forms]] impeding his progress, 'Vadamee reaches another piston. After traversing an open-air balcony full of battling Flood and Sentinels including an Enforcer, 'Vadamee activates yet another piston which takes him still deeper into the Wall.''

'''Vadamee fights his way through an area heavily saturated with [[Flood spores]]. Eventually he picks up another human transmission.''

*'''Stacker (COM)''': "Negative, ma'am! They are ''not'' Covenant!"

*'''Banks (COM)''': "Cover that doorway!"

'''Vadamee fights through another group of Flood and Sentinels before reaching another piston. He drops down a long tunnel which deposits him on a flat platform akin to the one he initially landed on. Nearby a Covenant Phantom is forced away by ground fire from several combat forms, leaving 'Vadamee to deal with them. He drops down another long tunnel and reaches the bottom of the wall.''

===100,000 Years War===
[[File:HTMCC-H2A Sentinel Factory Explosion.jpg|thumb|300px|One of the Sentinel manufacturing facilities explode.]]
''As soon as the doorway opens, an airborne [[Sentinel manufacturing facility]] can be seen in the distance as it is shot down by [[Zurdo-pattern Wraith|Wraith]] mortars and crashes into the [[Quarantine Zone]].''

'''Vadamee proceeds through the snow. {{Pattern|Udka|Assault Carapace}}s land across the canyon. [[Special Operations Sangheili|Special Operations]] [[Sangheili]] exit from them.''

*'''Special Operations Sangheili #1''': "[[Forerunner]]s be praised, the Arbiter!"

''With the assistance from fellow Sangheili, 'Vadamee defeats several waves of Flood.''

*'''Special Operations Sangheili #1''': "This Quarantine Zone has been compromised, we must do what we can against the Flood. Our [[Special Operations Commander|Commander]] has landed further in, let us join him."

'''Vadamee crosses a bridge and through a tunnel, engaging more Flood forms and meets the Special Operations Commander, [[Rtas 'Vadum]]ee.''

*'''Rtas 'Vadumee''': "Arbiter!? What are you doing here!?"

''Rtas 'Vadumee is interrupted by screeches of the Flood.''

*'''Special Operations Sangheili #2''': "The Flood is upon us!"

*'''Rtas 'Vadumee''': "We must hold this camp until reinforcements arrive."

''After the fight has gone on for a while, a Phantom descends from above, firing on any remaining Flood in the area. Fade to white.''

''Level ends.''

==Achievements==
The following [[achievement]]s can be unlocked on ''Sacred Icon'' across the [[Halo 2 (Windows Vista)|Windows Vista]] and ''[[Halo: The Master Chief Collection]]'' editions of ''Halo 2: Anniversary''. The original [[Xbox]] release of ''Halo 2'' did not contain achievement unlocks.
{| class="wikitable"
|-
! scope="col" style="width:135px;text-align:center;" |'''''Halo 2'' (Windows Vista)'''
! scope="col" style="width:135px;text-align:center;" |'''''Halo: MCC'' (Xbox One, Xbox Series X|S)'''
! scope="col" style="width:135px;text-align:center;" |'''''Halo: MCC'' (Steam)'''
! scope="col" style="width:175px;height:20px;text-align:center;" |'''Title'''
! scope="col" style="width:350px;height:20px;text-align:center;" |'''Unlock requirement'''
! scope="col" style="width:200px;height:20px;text-align:center;" |'''Games'''
|-
|[[File:H2V Achievement Sacred Icon.png|center|64px]]
|[[File:HTMCC H2A Achievement SacredIcon.png|center|114px]]
|[[File:HTMCC H2A Achievement Steam Sacred Icon.jpg|center|64px]]
|<center>'''[[Sacred Icon (achievement)|Sacred Icon]]'''</center>
|Beat Secret Icon on any difficulty.
|<center>[[Halo 2 (Windows Vista)|''Halo 2'' (Windows Vista)]]<br/>''[[Halo: The Master Chief Collection]]''</center>
|-
|<center>N/A</center>
|[[File:HTMCC H2A Achievement TerminalVelocity.png|center|114px]]
|[[File:HTMCC H2A Achievement Steam TerminalVelocity.jpg|center|64px]]
|<center>'''[[Terminal Velocity]]'''</center>
|Beat the par time on Sacred Icon.
|<center>''[[Halo: The Master Chief Collection]]''</center>
|-
|<center>N/A</center>
|[[File:HTMCC H2A Achievement GuidedTour.png|center|114px]]
|[[File:HTMCC H2A Achievement Steam GuidedTour.jpg|center|64px]]
|<center>'''[[Fists of Fury]]'''</center>
|Beat the par score on Sacred Icon.
|<center>''[[Halo: The Master Chief Collection]]''</center>
|-
|<center>N/A</center>
|[[File:HTMCC H2A Achievement Determined.png|center|114px]]
|[[File:HTMCC H2A Achievement Steam Determined.jpg|center|64px]]
|<center>'''[[Determined]]'''</center>
|Activate [[Terminal (Halo 2: Anniversary)|Terminal #8]] on Sacred Icon.
|<center>''[[Halo: The Master Chief Collection]]''</center>
|-
|<center>N/A</center>
|[[File:HTMCC H2A Achievement SkulltakerMythic.png|center|114px]]
|[[File:HTMCC H2A Achievement Steam SkulltakerMythic.jpg|center|64px]]
|<center>'''[[Skulltaker Halo 2: Mythic]]'''</center>
|Find and claim the [[Halo 2 skulls#Mythic|Mythic Skull]].
|<center>''[[Halo: The Master Chief Collection]]''</center>
|-
|<center>N/A</center>
|[[File:HTMCC H2A Achievement TheWilloftheProphets.png|center|114px]]
|[[File:HTMCC Achievement The Will of the Prophets Steam.jpg|center|64px]]
|<center>'''[[The Will of the Prophets]]'''</center>
|Collect the Arbiter toy in Sacred Icon.
|<center>''[[Halo: The Master Chief Collection]]''</center>
|-
|}

==Trivia==
===Glitches===
*[[Invincibility (Glitch)|Invincibility]] can be obtained via a glitch in the part where players fall down one of the tubes to see the Phantom for the first time.
*It is possible to encounter Marine enemies in the room where Sergeant Stacker and Sergeant Banks can be heard over the radio. A window shows a one-sided battle going on between a few Marine stragglers and Flood form. Going the normal route by turning the corner will trigger the Marines to die. However, using the Sputnik skull and some practice, the player can grenade jump across the window and completely bypass the trigger. If any Marines are still alive, they will engage the player as enemies. This trick also prevents the next few waves of Flood from spawning in the rest of this section until reaching the semi-outdoor area.
*The dead Marines and Brutes in this level [[Faking Brutes|blink their eyes from time to time]].
*The [[Jackals' unlimited Plasma Pistols]] glitch can be done on this level.
*During the fight with the first [[Enforcer]], if the player blows off all its attacking parts, the Enforcer will use its [[Invisible Sentinel beam]].
*If the player proceeds to power-up all Absorbers without destroying the Enforcer, it (with all Sentinel emitters and [[Sentinels]]) will self-destruct just before the door starts to open.
*It's possible to make a Flood Combat form freeze by jumping over it repeatedly.
*The [[Charging Needler glitch]] can be performed on this level.
*Sometimes the first Grunt in the level is invisible.
*The first Grunt encountered can be turned invincible when he falls down the tube. It only works with this one Grunt.
*In the beginning of the level, a [[BR-PR|strange weapon]] can be seen when the Phantom attacks the Enforcer. It appears to be a Battle and Plasma Rifle fused together.
*If any Grunts or Jackals follow the player up until the Buyer's Remorse checkpoint, they may become weaponless as their weapons disappear entirely. This appears to happen often when the player swaps any of the Grunts or Jackals weapons with a Plasma Rifle or Carbine Rifle (which only Jackals can wield in this scenario).
*There's a glitch that makes a fellow Elite weaponless. When you first get outside after fighting through endless flood in the facility and some Elites are dropped in to help you, you can give one of them an M6C Magnum pistol and it will disappear.
*This level contains several instances of the [[Halo 2 skulls|Thunderstorm skull]] not working properly. Even with the skull activated, several Grunt allies throughout the level can still appear as Majors instead of Ultras. Another example of this phenomenon is the first group of Brutes in the level [[Uprising (level)|Uprising]].
*If you melee a dead marine combat form in the hip, it will spin around, whereas if you melee it anywhere else, it will not move.

===Cut Content===
*There is cut dialogue that suggest at least one live Brute was meant to spawn as an ally.
*Three spawn points for Jackals to spawn in the containment shield chamber are present in the map files, but are obviously not active.
*An additional Sentinel spawner was meant to appear in the room that the underground Gondola goes, significantly higher up than the others.

===Miscellaneous===
[[File:H2-Containment_shield_panel_2.png|thumb|right|300px|The holo-panel featuring the six-digit hand.]]
*The holographic control panel for the Containment-Shield displays what appears to be a perfectly symmetrical hand, with two thumbs. The texture, created by [[Bungie]] environment artist [[Paul Russel]], was actually originally designed with a normal five-finger hand. However, due to texture memory constraints, the image was mirrored, creating the six-digit hand in the game. Paul Russel simply shrugged this off, thinking the Forerunners "were probably courteous enough to make their holo signage ambidextrous." Relatedly, later depictions of Forerunner hands in ''[[Halo 4]]'' and ''[[The Forerunner Saga]]'' established most Forerunners as having six-fingered hands with two thumbs.{{Ref/Twitter|docabominable|1605937566489776131|Paul Russel|Quote=It’s a mirrored texture. I thought the accidental two thumbs would be a funny thing to see fans speculate on. But it’s just mirrored to conserve texture memory. No secrets other than dev trickery to keep texture budgets low. https://archive.is/4ml2w|D=22|M=12|Y=2022}}{{Ref/Twitter|docabominable|1605938116597911552|Paul Russel|Quote=Oh, I remember thinking forerunners were probably courteous enough to make their holo signage ambidextrous. But I never told anyone that. https://archive.is/nqvUT|D=22|M=12|Y=2022}}{{Ref/Twitter|docabominable|1606022798270287873|Paul Russel|Quote=It’s really both. The texture had to be mirrored, so two thumbs was inevitable. I was able to shrug it off as ambidextrous but really no one cared. Just an item checked off a list. No mystery story meaning. https://archive.is/Dm99E|D=22|M=12|Y=2022}}
[[File:MTCC-H2A Containment Shield Peek.jpg|thumb|300px|An upcoming outdoor section being visible in ''Halo 2: Anniversary''.]]
*At times the player may initially find two Grunts and one Jackal instead of two Jackals and one Grunt, and on some occasions two Jackals and three Grunts. However, this is quite rare.
*Occasionally when sliding down the pistons alongside a Grunt, it may die on impact.
*When the Grunt is sliding down the first piston, it will sometimes stop just before falling onto another slide and refuse to follow the player any further. This can be avoided by letting the Grunt jump through first and pushing him down when the player jumps.
*There are voice files that indicate a Brute was supposed to appear as an ally early in the mission.
*As the player takes the gondola under the containment shield being deactivated, a future section of the wall can be seen on the right. Where as the section is darkened in ''Halo 2'' due to limitations of draw distance, it can be seen in ''Halo 2: Anniversary''.
*This is the first level to have Flood Infected Marines, Sentinel Majors, and Enforcers. It is also the first where the player can use Human Weapons while playing as the Arbiter.
*Because Sacred Icon is the first part of a two-part level, the player's weapons will carry over to [[Quarantine Zone]], unless one of the weapons is a Rocket Launcher. If the player completes Sacred Icon with a Rocket Launcher, they will start Quarantine Zone with a Covenant Carbine and an Energy Sword.

===Mistakes===
*Oddly, there appears to be stains near the Grunt by the piston at the start of the mission. It heavily resembles Flood matter, which would indicate the Flood managed to infiltrate the Sentinel wall before the containment shield was deactivated.
*The Arbiter fires three rounds at the Enforcer in the opening cutscene, yet his weapon is fully loaded when gameplay starts. There is no time for him to have reloaded offscreen.
*Snow falls through the last piston tunnel despite it being enclosed.
*One of four Elites who arrives by orbital insertion pod does not have a functioning energy shield.

*In ''Halo 2: Anniversary'', the opening cutscene shows the Phantom flying to the Sentinel wall backwards in one shot.
*The opening cutscene depicts the snow surrounding the Library as very vibrant. When gameplay begins the exterior is dark despite the platform the level begins on being open to the elements.
*In ''Halo 2: Anniversary'', the [[Sentinel manufacturing facility]] that the player sees being shot down by plasma mortars appears to explode on its own, as no mortars can be seen. This is likely because the plasma mortars depicted in the original game arc well beneath the factory, making the effect rather unconvincing.

===References===
*In the beginning of the level, the Arbiter can see the lakes where John-117 killed the High Prophet of Regret, just like how John can see the Sentinel Wall in the distance on [[Delta Halo]] and [[Regret (Halo 2 level)|Regret]]. In addition, ''High Charity'' appears to be very close to Halo.
*In the beginning of the level, there are patches of Flood blood near the Grunt which indicates the Flood has made it far enough to the point of escaping.
*Originally, Bungie had planned for there to be an additional level after Sacred Icon called "[[Forerunner Tank]]." It was cut, however, due to deadlines.<ref>Halo 3 Essentials, Disc 2, Halo 2 Audio Commentary.</ref>

*This is the first of two levels in the Halo trilogy where the player can wield the blue Sentinel Beam.
*There is speculation on why the Arbiter is able to use the Forerunner systems on this and other levels. The Forerunners made it to where no one but themselves and the Humans would be able to use the systems on the Installations that they created, but it is shown that the Arbiter can use them as well. This is likely an oversight made by Bungie and the Halo creators. Examples of this is when the Arbiter takes down the Containment shield on the Sacred Icon and when Rtas 'Vadumee activates the Gondola on the Quarantine Zone. It's possible that Forerunners allowed minor systems to be used by any species, like when the Covenant lock a Forerunner door in The Silent Cartographer level, but made sure only Reclaimers could do major things such as activating a Halo or retrieving the Index.
*All the dead [[Jiralhanae|Brutes]] in the level are lying in a pool of blue ([[Grunt]]) [[blood]]. Same with [[Kig-Yar|Jackals]] that are dead before the player arrives. It is possible that the Grunt's that the blood originated from were swept away or devoured by the Flood.
*This is the only level in the [[Halo Trilogy]] that features [[pistons]].
*During the development of ''Halo 2'', the level was known by the working title ''"Sentinel Headquarters"''.<ref>[http://www.youtube.com/watch?v=GHoTMhq0vzE?t=7m15s '''YouTube''': ''The Making of Halo 2'' (07:15)]</ref>
*This is the only level in the entire game where Jackals appear as allies.

===Easter eggs===
*The [[Halo 2 skulls#Mythic|Mythic Skull]] can be found on this level.
*Throughout the level the player can find weapons containing more rounds than their capacities, including [[BR55 Battle Rifle|Battle Rifles]], [[M6C Magnum Sidearm|Pistols]] and [[Type-33 needler]]s .
*A [[Type-33 needler]] can be found in the room where the player encounters the first [[Enforcer Sentinel]]; this particular needler has 1 round loaded with 6 in reserve. Totaling [[Seven|7]] rounds. 
* The eighth terminal is a Covenant terminal in the room with the final piston of the level. The room is easily identified by the fact that it is completely devoid of combat; the only Flood in the room are dead. The terminal is behind a wall on the right side of the room.

==Gallery==
===''Halo 2''===
<gallery>
File:H2 header - Sacred Icon.png|Preview of the level in ''Halo 2'' menu.
File:Honor Guard Ultra Helmet.jpg|The changing of the guards outside the Inner Santcum.
File:Halo6.jpg|A Phantom approaches Installation 05.
File:H2 Arbiter Ready.jpg|The Arbiter prepares for his mission.
File:Enforcer sneak.jpg|An Enforcer sneaks up on the Arbiter.
File:H2_SacredIcon_EnergyAlley.jpg|One of the numerous energy alleys encountered throughout the level.
File:HTMCC-H2 Constructor&Piston.png|A Constructor Sentinel interfaces with a piston.
File:HTMCC-H2 SentinelWallDeactivates.png|Tartarus' Phantom swoops in as the containment shield deactivates.
File:HTMCC-H2 SacredIconSpecOpsCamp.png|Rtas 'Vadumee manning a Shade in the quarantine zone.
</gallery>

===''Halo 2: Anniversary''===
<gallery>
File:H2A Medium ForerunnerCrate Concept.jpg|Concept art for one of the Forerunner crates on the level.
File:H2A ForerunnerWall Concept.jpg|Concept art for one of the corridors inside the Sentinel Wall.
File:H2A - Arbiter and former guardsmen.jpg|The Arbiter meets two Sangheili relieved of their guard posts.
File:H2A - Brute Guardsmen.jpg|A Jiralhanae Honor Guard snarls at the Arbiter.
File:H2A - Rtas with Truth.jpg|Rtas 'Vadum speaking to Truth and Mercy.
File:H2A - Hierarchs with Vadum.jpg|The Arbiter enters the Inner Sanctum.
File:H2A - Library.jpg|The Library being protected by the Sentinel wall.
File:H2A-InfectedHumans.png|The Arbiter encounters human Flood combat forms in the Sentinel wall.
</gallery>

==Sources==
{{Ref/Sources}}

{{Succession box | before = ''[[Regret (Halo 2 level)|Regret]]'' <br />| title = [[Halo 2 Campaign|''Halo 2'' Campaign Missions]] | years = '''''Sacred Icon''''' |after = ''[[Quarantine Zone (Level)|Quarantine Zone]]''}}

{{Levels|H2}}