Destruction of the Black Engineers

The Destruction of the Black Engineers was an Imperial joint-castigation campaign carried out by both the Ebon Knights and the legendary Grey Knights Space Marine Chapters. They were responsible for the persecution and eradication of the renegade Heretek faction of Tech-Priests known as the Black Engineers, for dabbling in 'Malatek Incarna'.

History
Stationed at a remote Adeptus Mechanicus research facility, a group of Tech-Priests had banded into a heretical techno-cult known as the Black Engineers. In their testing chambers, they began to explore long-forbidden sciences that was outside the purview of the Cult Mechanicus. Their heretical research resulted in a disastrous resonance cascade that tore a rift in reality which devastated the facility and enabled daemons to manifest in the material realm. Crusading in close proximity, the Ebon Knights answered the research facilities astropathic distress signal and made all haste. When they arrived, they fought alongside the mysterious silver-armoured Astartes of the legendary Grey Knights amongst the ruins of the research facility an attempt to eradicate the daemons and seal the rift. The surviving techno-cultists surrendered and were executed for their tech-heresy.