Thema

A thema was a semi-physical and logical division of the galaxy created by the Forerunners. Each thema contained a number of star systems. A thema was bordered by massive rippling magnetic fields of a galactic scale.

Forerunner displays simplified and projected the complex variability of a thema boundary as a curtain of colored light. These borders were detectable in realspace and slipspace. From the projected color of the field and the vortices within it, the overall health of slipspace could be determined.

By the end of the Flood-Forerunner War, the boundaries of themas became more unstable as the Precursors gradually converted slipspace to become incompatible with Forerunner slipspace drives.

Known Themas

 * Thema 34
 * Nomdagro
 * Thema 78
 * Path Terrulian
 * Thema 102
 * Path Nachryma

List of appearances

 * Halo: Silentium