Mission to Installation 03

The Skirmish on Installation 03 was an engagement on the surface of Forerunner Halo Installation 03 in the Khaphrae system and at the Composer's Forge on July 25, 2557, between the United Nations Space Command and the Didact's Prometheans.

Prelude
Upon discovering Installation 03, following the Battle of Tribute, the Office of Naval Intelligence conducted numerous searches on the Halo. One of the objects they discovered on the installation was the Composer, a piece of Forerunner technology that could transfer organic being's mental content into machine data. The Composer was brought to Ivanoff Station, a research facility located on one of the asteroids orbiting Installation 03, for further study. On July 24, 2557, the Didact arrived at Ivanoff Station to recover the Composer.

He used it to compose the citizens of New Phoenix on Earth, but was ultimately stopped by John-117. During the battle, John-117 caused the Didact to fall into a slipspace rupture. However, the Didact survived and crash landed on Installation 03. During this time, a science team, along with Spartan Team Black, were still on Installation 03's surface, unaware of what had happened at Ivanoff.

Installation 03
On the installation, the science team and Team Black established a camp on one of the ring's deserts, nearby the Composer's original location on the installation. However, the Didact, along with several Promethean Knights and Crawlers, arrived via a slipspace portal and crash landed near Black's location. When Black went to investigate, the Didact awoke and swiftly killed all four Spartans. At the same time, the science team was attacked and killed by Promethean Knights and Crawlers. Shortly afterwards, the Didact encountered 859 Static Carillon, monitor of the Composer's Forge, who had come to investigate the opening of a service portal to the ring. The Didact demanded that Static take him to the Composer's Forge. Static agreed, on the condition that the Didact would not use the Forge to produce more Prometheans.

Due to the loss of contact with the team, Lord Terrence Hood sent Blue Team, consisting of Fred-104, John-117, Kelly-087, and Linda-058, to investigate Team Black's disappearance. Blue Team took a GA-TL1 Longsword to Installation 03 and landed near the research camp.

While walking to Team Black's last known position, Linda discovered Crawler footprints in the sand leading to the camp. As Blue Team entered the camp, they discovered the corpses of several researchers. Shortly after, Fred found the bodies of Team Black, dead. While looking for Team Black's assailant, the Spartans were attacked by Promethean Knights. After a short firefight, Blue Team destroyed the Knights and discovered the former location of the Composer. Upon entering the structure, the Spartans discovered the Composer's Abyss, a facility used to store victims digitized by the Composer. At the end of the Abyss, the Spartans discovered a slipspace portal.

The Composer's Forge
After they entered the portal, Blue Team arrived in a seemingly empty Forerunner city. They moved further into the city and soon discovered six Composers, just before the Didact appeared behind the Spartans. Holding an activation index, the Promethean leader told Blue Team that they have arrived at the Composer's Forge. Blue Team open fired, to no avail; the Didact stomped the ground, generating a shockwave that caused the Spartans to stumble and fall to the ground. The Didact summoned more of his Promethean minions and a frantic firefight broke out.

859 Static Carillon arrived at the scene, furious that the Didact violated their agreement in having created more of the Promethean constructs, which it deemed abominations. In retort, the Didact ordered the monitor to fulfill its part of their bargain. The monitor obliged, and a Halo installation appeared in the sky over the Forge from slipspace. Satisfied, the Didact stated that he will repair the ring; Static Carillon told the Spartans that the Didact was planning to use the Halo against humanity and Earth. Furthermore, while it was indifferent to mankind's fate, the monitor took issue at the Didact's creation of new Prometheans from the humans of New Phoenix, viewing the Prometheans as instruments of terror and chaos and deemed their presence on its installation unacceptable. Static Carillon helped the Spartans retreat back to the Gamma Halo portal in pursuit of the Didact, holding off the hordes of Promethean machines. As the Spartans entered the portal, Static Carillon told John that he would attempt to close the portal behind the Spartans.

Return to Gamma Halo
Blue Team returned to the surface of Installation 03 from the Composer's Abyss and made it just in time to witness a Composer rising from the Abyss. John fell behind the rest of Blue Team — due to his conversation with Static Carillon — while the Didact confronted Fred, Kelly, and Linda. The Didact attacked the Spartans and prepared to finish them off, unaware of John's location. As the Didact was about to execute Kelly, the John snuck behind the Forerunner and stabbed him in the eye with a combat knife. Intending to correct his mistake of not having killed the Spartan when he had the chance, the Didact grabbed John by the head, lifted him in the air, and crushed his helmet.

List of appearances

 * Halo: Escalation