Burn

A Burn was a Forerunner term for a region of the galaxy - a thema or margin arc - infested by the Flood and abandoned by the Forerunners. As the Flood continued to spread exponentially, Burns rapidly expanded over Forerunner territory. A tactical transmission recorded sometime in the last decade of the Forerunner-Flood war reported that Burns extended across the entire galaxy, covering two-thirds of formerly Forerunner-controlled space, with the Flood in complete control of well over five hundred thousand star systems.

Due to the dangers of reconciliation imposed by the Flood presence in the Burns, travel within them was prohibited by Ecumene authorities, with only warships permitted to enter them. Of note were the s, who were deployed into Burns as part of trident spires and tasked with performing hit-and-run strikes on Flood-dominated planets. The second-order fast frigates were also permitted to enter them due to their ability to navigate slipspace. The Warrior-Servants continued to operate facilities inside Burns, and used them as training compounds for their troops. One such example was recreated by the United Nations Space Command for their own War Games testing.

In 2558, Catalog reported that Forerunner fleet command had designated the Boomerang Nebula as a burn, additionally recording that the nebula had been the site of star roads during the war with the Flood.

List of appearances

 * Halo: Silentium
 * Halo 5: Guardians