Library

The Library is the name given to a structure present on each of the Halos created by the Forerunners.

Background
The Library's true function is unknown at present. However it is hypothesised to be a collection of all information regarding the Flood known to the Forerunner and also collated cloned DNA sequences. All of this information is contained within the Index contained within the Index Chamber and is used in the process of activating the Halo system and wiping the galaxy clean of sentient life and that which has sufficient biomass to sustain the Flood.

The Index is housed in suspended animation within the core of the Library, out of reach of possible Flood outbreak. The only access to it, internally, is via a giant lift that descends from the highest level of the Library to the Index's suspended position.

Access to the Library itself usually occurs via each installation's internal teleportation grid. On Installation 05 2401 Penitent Tangent was unable to assist the Arbiter in this manner. As a result a longer, less direct route had to be taken. An Anti-Gravity Gondola spanned the distance between a Forerunner base and the Library. This large Forerunner base was the Sentinel Wall which was protected by an energy shield and filled with hundreds if not thousands of Sentinels and Enforcers. Then, beyond the wall is an artificial lake and a great chasm that the gondola must cross.

On both Installation 04 and Installation 05 the Flood was still able to breach such defenses and infest the Library. This may indicate that the Library is not as secure as the Forerunners had hoped it would be or that it was initially a containment facility for the Flood. The interior of both Libraries consists of multiple gigantic hallways of geometric design interconnected to one another, finally leading to the Index Room.

The Library of Installation 04
343 Guilty Spark teleports the Master Chief from the swamp lands of Halo, after deeming him to be a Reclaimer, into the Library of Installation 04. Equipped with basic weapons he embarks on a near-suicidal mission to reach the Index, with legions of Flood standing in his way.

It is here that 343 Guilty Spark remarks upon both the nature of the Flood and the Forerunners. Making specific reference to the their technological superiority, he wonders why the Chief had brought "such ineffective weapons to combat the Flood". Guilty Spark also recommends that the Master Chief should upgrade from his current MJOLNIR armor, a Mark V (which according to an unknown Forerunner ranking system is only Class 2) to a Class 12 Combat Skin, which is stated as a necessity in order to combat the Flood.

Towards the end of this Library, the Chief encounters the body of a Marine who was Guilty Spark's most recent, but failed, Reclaimer. In the second Halo novel, The Flood, this Marine is said to have been so mutilated that the Flood could not possibly take over him. He is identified to be Staff Sergeant Marvin Mobuto.

The Library of Installation 05
In Halo 2, whilst the Master Chief hunts down the Prophet of Regret, Commander Miranda Keyes, Sergeant Johnson and most of the Marines attempt to break into the Library in order to find and retrieve the Index. Due to the significantly larger Flood outbreak on this Installation, the Library and its defenses are seriously damaged and as a consequence filled with vastly larger numbers of Flood than its counterpart in Installation 04.

The Arbiter travels to the Library of Delta Halo. This journey encompasses the Sacred Icon and Quarantine Zone levels. Dropped into the Sentinel Wall from Tartarus' Phantom, the Arbiter battles his way through swathes of Flood and Sentinels to find the gondola that will carry him into the core of the Library. By removing the containment plugs, the Containment Shield guarding the Quarantine Zone can be lowered, enabling the Arbiter to enter the Library properly. Unfortunately, this also releases the Flood adding to the magnitude of the outbreak.

The Arbiter takes the gondola into the depths of the Library to find the Index chamber. This inner section of the Library is identical to that of Installation 04's. After being thrown to his death by Tartarus, the Arbiter is rescued by the Gravemind, who then held him captive for his own motives. It should be noted that in the Index Room there is what appears to be multiple destroyed Enforcers, as well as a number of the Gravemind's tentacles. This may be an indication that at least part of the Gravemind exists within the Library itself.

The Library of Installation 04 (II)
Although it is never seen, it can be assumed that the Library of Installation 04 (II) is identical to that of its predecessor. One can infer this for the simple reason that the Control Room is identical between the structures as well.

Trivia

 * The structure of the Library is similar to the symbols on the stone slabs on the top floor of the bases in the Halo CE map Blood Gulch. It could mean that the structure of the Library is somehow related to Blood Gulch, or that it is simply a common Forerunner symbol.

Related Links

 * Index
 * Halo
 * Control Room