And it was this octahedral obelisk that had made the cavernous chamber a shrine, certainly; it was the reason why the cultists had congregated at this place. And what Gdolkin took to be the last of the Shinarii were gathered there now, still numbering around two hundred, the Iron-Father estimated. The black-robed cultists were prostrating themselves before the towering monolith, offering obeisance as they chanted in the dark tongue of their creed.

Gdolkin could not understand the words they were intoning, thank the Emperor, it was just a meaningless babble to his ears. But that did not mean that he could not understand its purpose. The Iron-Father could sense fell powers at work here, within this place, although whether the rite was intended to activate the artefact or destroy it, there was no way of knowing - at least not yet. The acoustics of the cave made the chanting rebound and redouble, lending it a throbbing quality that passed through Gdolkin. It made his ears itch to hear it and his stomach knot with the feeling of nausea.

The Iron Hands had scrambled up a steep incline, the sound of the chanting becoming clearer and louder with every step, until they had emerged onto a naturally formed ledge, a pillar of element-sculpted rock partially obscuring the position so that the Space Marines could look down on the cavernous chamber that opened up before them without being seen by those already inside They had encountered no opposition, no sentries or early warning systems. Obviously the Shinarii were either complacent about their position or the ritual occurring now before his eyes was of such importance that all their attention was focused on that and that alone.

'Finally, the last of the Araken artefacts!' Magos Thule's voice hissed.

'Silence, priest!' Gdolkin snapped back under his breath, over the vox. 'Would you give our position away?'

'But I must take readings from it, before it is too late.'

'What we must do is destroy that thing and bring about an end to the ritual before these cultists can bring harm to this world-'

Gdolkin broke off in mid-sentence as his finely-tuned ocular implant saw something else enter its field of vision, something that suddenly made what they had seen so far make more sense and yet which also impressed upon him the seriousness of their situation.

The other Iron Hands glanced at their leader, wondering what had caused him to break off so abruptly. All were impelled to look to where he was gazing, so intent was his stare.

An armoured figure, as tall as a Space Marine, was approaching the edge of the obelisk pit through the throng of bowing cultists. He was accompanied by a squad of seven other warriors. All were clad in the same manner, baroque suits of power armour, the colour of dried gore, the leader's trimmed with bone. The blasphemous markings etched into the surface of the ceramite plates and the curling, ridged horns rising from their altered helms spoke of their vile allegiance.