Foramen Ignotum collapses

On 1012.019M42 the reason for fighting over Hexis, the necron device powering the Foramen Ignotum, abruptly stopped working. The consequences were immediate, as the stable channel that sliced through the Cicatrix Maledictum collapsed, plunging any vessel in the channel into the madness of the warp. Thousands were killed, as were hundreds more on Hexis, as the ground above the device chamber, where many were working on analysing the energy flux from the device, or stationed nearby to protect the inner city, gave way. The earth shook for many minutes, with a force that was felt in general Konev's HQ. When the shaking stopped, the centre of Praxis had disappeared into rubble, and the energy signatures from the device had shut off completely.

Shock soon turned to recrimination in the Imperial HQ. How had this happened? Who had disabled the very artefact the Imperium had shed so much blood to control? Sadly, General Konev already knew. Days before, an Inquisition party had arrived, bearing orders from Inquisitor Vorushko, to "investigate" the device for the good of mankind. Konev had no choice but to acquiesce to their orders, and while the Grey Knights secured the device chamber, the small party made its way secretly to the device chamber and there, somehow shut down the artefact.

The Inquisition did not explain what or why they had carried out the act, but the collapse of the Foramen, they said, was "necessary" for the good of mankind and the Imperium. The inquisiton then left as quickly as they had arrived, leaving a war torn planet and the inert remains of a now useless alien device, buried under a mile of rock.