SUMMARY
The Battle of Installation 03 was a battle between the UNSC and Covenant remnant forces under command of Jul 'Mdama on Gamma Halo during and immediately following the New Phoenix Incident in July 2557. While John-117 was chasing down the Ur-Didact following the Battle of Requiem, a large contingent of Jul 'Mdama's forces discovered that the Conduit, a Forerunner device used to open portals across the galaxy, was located on Installation 03, and headed to retrieve it. Initially 'Mdama's forces used the Conduit to bring Forerunner Prometheans to Gamma Halo in order to take control of it, and after the Conduit was recovered by the UNSC, they used the Alter on Installation 03 to open a portal to New Phoenix, Earth.
RELATED MEDIA
These events are depicted in the video game Halo: Spartan Strike.