The Sentinel Wall is a massive wall built by the Sentinels surrounding the Quarantine Zone around the Library of Installation 05 to keep the Flood from spreading. [1]
Background
History
The Wall appears to have been designed to keep the outbreak of Flood around Delta Halo's Library contained within the Quarantine Zone. It is honeycombed with tunnels for the Sentinels to travel through. Sentinels and Enforcers keep the Flood contained, while Constructors keep repairing the damage that the Flood inflict on the Wall. It is possible that their is constant battle in the Quarantine Zone, as in the level of the same name, Flood and Sentinels are seen in many instances fighting one another.
Battle of Installation 05
Despite the efforts of the robotic keepers, the Flood were released when the Arbiter penetrated the defenses and deactivated the containment shield around the wall. It is unknown if such a structure exists on the other Halo installation's. During the battle on Installation 05 the Arbiter was sent into the wall to deactivate the shields keeping the Flood in the Quarantine Zone in order to let other Covenant forces fly over the wall towards the Library. It is possible that this is what caused the Flood to be able to capture Covenant craft and attempt to use them to escape Halo, as seen in Halo: Ghosts of Onyx.
Trivia
- Sentinel Walls are means of containment if primary measures fail.
- A section of the Sentinel Wall is clearly visible on the Halo 2 Campaign levels Delta Halo and Regret, as well as Multiplayer map, Containment, a multiplayer map only featured in the Halo 2 Multiplayer and Halo 2 Vista map packs.
- Complying with the above statement, the Sentinel Wall can be visible and seen beyond the Prophet of Regret's Forerunner Temple on the level Regret, denoting its massive structure and size.
- It is unknown whether the other Installations have this feature or one in similar function. Installation 04 didn't have a known Sentinel Wall.
- Canon dictates that all of the Installations have varying environments, making the existence of these walls more unclear.