Dead Scar

A series of corrupted and shattered stations which represent a massive hole in the Hephaestian defense network. Done by the Black Legion and Nurgle forces during the first wave of assaults at the turn of the millenia, many of the stations have never been able to be fully cleansed or destroyed. So thin is the hephaestian armies spread.

The stations are not in a line all the time, but when the stations orbits

line up every 29 years, a direct space channel through the system defenses opens up, and it is all the Mechanicus can do to hold back whatever swarms through.