The affair began when Ordo Malleus Inquisitor Lord Antonius Coil discovered Warp taint on the Imperium world Goleonda IX originating from the Dark Mechanicus Forge World of Sarum. After ordering an Exterminatus on Goleonda IX, Antonius gathered a strike force to destroy Sarum and finally end its threat to the Imperium. He assembled a mighty force composed of ships from Battlefleet Reductus, several Militarum Tempestus Regiments, and had aid from the Sons of the Raven, Celestial Guard and the Brazen Claws Chapters. However, when Antonius' strike force neared Sarum it was ambushed by the Warbands of the Warp Ghosts and Black Wings, as well as the Daemon Engines of their Dark Mechanicum allies on Sarum. The Inquisitor Lord was killed in the seventeen hour void war that followed and only the forces of the Brazen Claws and Celestial Guard were able to escape the strike force's destruction.