Line installation

A Line installation is a Forerunner defensive outpost, part of the Maginot Line, intended to prevent enemy ships from reaching the inner worlds of the Orion complex.

Background
The Maginot Line, or Jat-Krula as it was known to the Forerunners, was constructed over half a million years before the firing of the Halo Array as the ultimate defense for the inner systems of the ecumene. The Line installations, numbering in the millions, were placed in strategic locations, particularly along the most efficient and well-known slipspace pathways, forming an enormous sphere surrounding the Orion complex. Any incoming enemy ship or fleet would have to pass through the perimeter, where it would be targeted and destroyed in slipspace by the Line installations in range. These installations are usually located on a planetary body, such as a natural satellite.

As part of the Forerunners' efforts to contain and understand the Flood, some Line installations were refitted to serve as Flood research facilities. These installations employ machines known as Gatherers, specialized for collecting specimens for analysis. Each Line installation also has its own monitor and a control center, as well as a sizable force of Sentinels.

History
During the Forerunner-Flood war, Line installations were used as containment measures against Flood-controlled spacecraft, meant to prevent them from reaching the Forerunner core worlds. However, in the later years of the war, even these measures began to fail and the Flood would occasionally slip past gaps created in some segments of the boundary.

During the Human-Covenant War in the late 2552, the Long Time Coming, as well as the Covenant assault carrier Clarity of Faith were shot down by Line Installation 1-4's defenses while in Slipspace. As a result, they both crash-landed on a moon in Sub-sector 35 which was also home to Line Installation 1-4. Personnel were taken by Gatherers into the main facility of the installation, for study by the installation's Monitor, 686 Ebullient Prism. During the Battle of Line Installation 1-4, the installation's control center was located and used to shoot down an entire Covenant fleet in Slipspace.

Known Line installations

 * Line Installation 1-4
 * Line Installation 9-12

List of appearances

 * Halo: Blood Line
 * Halo 4
 * Halo: Silentium