Installation 08

Were you looking for the original Installation 04?

"A replacement, for the ring you destroyed."

- Thel 'Vadam observing the second Installation 04's construction alongside John-117.

Installation 04B was a partially completed Halo Ring which began construction at the Ark after the destruction of the original Installation 04.

Background
This Installation was designed as a very similar replacement to the original Installation 04 in order to ensure that the Forerunner's Halo Network was intact, and therefore able to encompass the entire Milky Way galaxy.

Creation


Following the Battle of Installation 04 and its subsequent destruction, the Ark was notified, and an automated function began building a new replacement for the missing Installation's position.

The main weapon was built first with the surrounding circular metal structure after it. It is unclear how the Ark was able to create the new installation or what the source of raw materials for its construction was, as no insight is given to those functions of Installation 00. It is possible, though, that the materials came from the Ark's Core, a planetoid located at the center of Installation 00, as the core seems to have large areas torn away from the surface and is also located at the center of the Ark's foundry, where this ring was built.

Before it was released into space (presumably work was to finish there before being sent to Threshold to replace the original Installation 04 destroyed at the end of Halo: Combat Evolved), the Installation had a number of primary features available even though it was still not complete. These included the environment, atmosphere and main structures, and the main weapon, though the ring structure was not yet stable enough to survive this weapon's discharge.

The ring was also not connected to the other Installations, allowing a tactical pulse to be fired without triggering the other six Installations. It is never revealed if this is an option available to completed Installations as well, although it is likely the second Installation 04 merely had not been set up with this network yet, as it was incomplete; a logical precaution considering the effects of a misfire.

In the Halo Legends short film, Origins, it is revealed that the Ark will produce an enormous Slipspace portal large enough to transport a ring if needed. This is possibly the only way for the ring to get to its intended destination, as any other method would seem very unlikely.

Discovery
The new Installation was released into space just above the Ark, but it was still incomplete then. The Master Chief and the Arbiter decided that the only way to stop the local Flood infestation (which included the Gravemind from Installation 05) was to fire the incomplete Installation, which was out of range of the other rings.

The Chief headed to the Flood-controlled High Charity to retrieve Cortana, as she held the Activation Index from the first Installation 04. Aided in his escape by the Arbiter, the Chief found a crashed Pelican near the exterior of High Charity and piloted it to the Control Room.

The Pelican crashed in a snowy valley near the Control Room, which was situated atop a high tower (much like the original Installation 04's). As the Chief and Arbiter made their way towards the tower, Flood dispersal pods descended from the sky and the Gravemind revealed that he was not yet defeated.

After battling to the top of the tower, aided by Sergeant Major Avery Johnson and his Spartan Laser, the team reunited with 343 Guilty Spark.

Destruction
As they entered the Control Room, Spark stated that "this Installation should be ready to fire in just a few more days," and that "a premature firing would destroy the Ark" and the ring. However, due to the gravity of the situation, Johnson told Spark to "deal with it" and attempted to unite Cortana with the Control Room's core.

This proved too much for the already partially rampant 343 Guilty Spark, who regarded the Installation as his. He entered full Rampancy, and fired on Johnson with his enhanced Sentinel Beam, mortally wounding him.

The Chief rushed to Johnson's aid, but was knocked down by Spark's beam, which was then turned on the Arbiter, who was knocked out of the door, which closed. As the Master Chief tried to get up, he was fired upon again. However, his shield took most of the blast. In the ensuing battle, when the Chief was cornered, Johnson fired his Spartan Laser on Spark before lapsing into unconsciousness; this stunned Spark. Johnson gave the Laser to the Chief with the words, "Kick his ass." After three shots from the Laser, Spark exploded, and the Chief was finally able to unite Cortana and the Core.

As Spark predicted, the ring was not ready to fire, and it began to shake itself apart and disintegrate. Master Chief attempted to save Johnson, but he replied with only "Send me out...with a bang," before closing his eyes. Master Chief and the Arbiter escaped through the second Phase Pulse Generator (the first is hidden in the cliffs) and then to Johnson's Warthog. The vibration of the activation began to tear the Installation apart, causing explosive reactions all across incomplete sections of the installation. The Chief and Thel 'Vadam barely managed to reach the UNSC Forward Unto Dawn before the ring exploded. Cortana stated that the ring's explosion "did a number on The Ark".

Trivia

 * In the Control Room, the hologram of planet Threshold is missing and if the control room is viewed from above, it looks like an entirely black circle. If Threshold was present, the circle would have an orange center. This draws parallel to a glyph during the Iris campaign, which was missing the circle in its center compared to all the others.
 * The map Avalanche from the Legendary Map Pack is located at this Installation's Control Room, but the Ark and the Milky Way are missing from the skybox.
 * This Installation would have had a Flood Containment Facility, just like the first Installation 04, although there would be no Flood to be transported to them at that time.
 * It seems that key places like the Control Room and the Silent Cartographer would be on the finished parts of the ring, as the Control Room had at least a mile of complete, sound structure around it.
 * The near-completed Installation shows the prowess of the Forerunners' stellar engineering as it was built completely from scratch in a matter of months.
 * If this Installation had been completed, it is unknown if it would have gone to Threshold or somewhere else.
 * The Control Room tower resembles the tower seen on Installation 04, but the corridors on the inside are more like those seen on Installation 05; the directions turned are the same, while in Halo: Combat Evolved, it was almost straight. The Control Room itself is the same as the original Control Room of Installation 04. It is likely that this was an oversight, or it could show that the design of the Halo rings is constantly updated.