Imperium find means to activate device.

In late 01.019M42 a chance discovery turned the Hexis campaign on its head. The imperium had twice captured the device room already, but both times the Adeptus Mechanicus had failed to unlock the secrets of the ancient artefact, despite extensive records shared with them by inquisitor Vorushko. 

By 1501.019M42 the imperial cult forces who had previously occupied the centre of Praxis had been pushed out by the combined efforts of the Chaos Pact, with mercenary orks dealing the final blow. The Foramen had been activated and changed alignment once already, with the chaos forces apparently learning the secrets of the xenos technology. This alarmed the imperium, but also gave the Mechanicum renewed drive to solve the problem. The imperium lacked information however. This changed on 1801.019M42, when the Grey Knights accidentally discovered the imperial cult had the vital intelligence all along. 

The Grey Knights initially took a deep dislike to the imperial cult, seeing them as reckless and borderline heretical forces, not under the direct control of imperial command. Konev however was a skilled diplomat, and over time managed to convince Inquisitor Hector Rex of the faithfulness of the cult, as well as their military worth. This took time as all communications with Rex had to be sent and received by astropath, as the inquisitor lord was still at Destino investigating Cybixx. Eventually though, the Ordo Malleus agreed to accept the cult and even provide them some training, after they had been subject to a thorough investigation by his agents and the Grey Knights. 

The training proved to be sorely needed, as while the imperial cult had been successful at small scale engagements and the guerrilla warfare in the tight streets of central Praxis, they suffered badly at the hands of the astartes in a pitched battle scenario. However, the investigation by the inquisition found that the cult had collected several strange looking artefacts of xenos origin, which they intended to have delivered to the Ecclesiarchy for their destruction. These artefacts were confiscated by the inquisition, and the cult told that any further items of interest must be immediately handed over to the Mechanicum. Amongst these items were crucial pieces of evidence which finally gave the Adeptus Mechanicus the knowledge they lacked. Deeply heretical nonetheless, the inquisition decided to oversee all further work on necron technology, much to the irritation of the Mechanicum. Now though, the imperium believed they could finally control the device, and plans were hastily put in place to retake control of Praxis city centre. The faster they could change the alignment of the Foramen the better.