The Haydex Deep Recovery team was dispatched more than thirteen hundred cycles past... They're fathom-bore running expedition was tasked with one sole mission, to recover the lost ancestor core that was brought to Aranthus Prime in the Dark Age of Technology, before it was rechristened Necromunda. 

When whatever ancient tragedy consigned it deep beneath the industrial slag, some of the Ironhead could not accept it's loss. They turned their backs on their ancestral charters and continued to delve deeper than any Underhive or geothermal heat sync.

That they found something in the depths is not disrupted. It is quite possible the Haydex Kyn even did find the lost core... It is also possible the ancient machine has been alone in the deep far too long, perhaps something else found it first, or they found something else entirely?