The Foramen Inderdictum

The Foramen Interdictum is a gateway, a stable passage, between the Dark Imperium and the rest of the galaxy. It lies in the Aleph subsector and bisects the Cicatrix Maledictum at the junction of the Minoris arc, just to the galactic south west of the planet Corticant, currently controlled by the Imperium.

The Foramen has two passageways, Foramen Maximus, the longer of the two stable tunnels, projects outward from Corticant, across the warpscar, and into the Perseus Void near the Necron planet of Zog. The other passageway is narrower, more dangerous and prone to collapse, but flickers on and off across the Cicatrix Minoris, via the Foramen Minoris, connecting a line towards Parthenope and the Vastrid subsector.

the opening of the Foramen occurred at sector time 2109.017M42, when the necron "device" on Corticant was activated by agents of the Inquisition. Vorushko had realised just in time the significance of what she thought initially were heretical chaotic devices which needed eliminating. Working with Inquisitor Huron, ordo Xenos, the Inquisitors realised the effect the necron device would have, connecting the Dark and Light sides of the galaxy.

Initially Vorushko considered simply letting the Dark Imperium wither and die, while concentrating on rebuilding the stronger half of Mankind, but with Roboute Guilliman on crusade, she decided against it. Besides, after weeks of being adrift she eventually found out she was on the wrong side.

Vorushko's team were successful in activating the necron device against Inquisitor Hathek's express wishes, and the newly active device immediately began creating the Foramen, pushing back the warp and allowing stable warp transit of the Cicatrix Maledictum.

It quickly became clear however that the strategic significance of the Foramen was simply incredible. Moreover, the Foramen Maximus ran close to the chaos daemonforges of Mordecai and Kendrenec, while also in easy reach of the Federacy and fleets from Farpoint and Bastien in the Imperium. Protogonus, the Tau outpust, also stood in easy reach, and the passage itself directly connected the Harakhty and Charnovokh dynasties. In addition, without control of a passage, there was no possibility that Hive Fleet Nemesis would be able to cross over into the heavily populated Vastrid subsector. Whoever controlled space and planets around the Foramen, controlled the Aleph Sector...