Moab - Sorrow of Moab: At the same time the Death Guard Legion was leading the assault on the sub-sector-capital of Dominica Minor, Moab also came under attack; not by the pale-hulled warships of the Death Guard, but the deep viridian and sable vessels of the Sons of Horus. Using the neighboring gas giant for cover, eight strike cruisers of the Sons of Horus warfleet approached the planet -- at their apex was the Ikon, the dreaded vessel that had already delivered the Warmaster's ultimatum to other worlds such as Gethsamaine and Taracanis.This time the Ikon and her companion warships directly opened up on Moab's primary orbital station with their Accelerator Cannons, easily overcoming the station's defences and it was quickly boarded. The attack had been so sudden that Moab's ground defences barely had time to retaliate before the attacking vessels retreated again out of range of the planet's guns. Willing to spare his domain the devastation and death of a Legiones Astartes-led planetary assault, Malthus Grange quickly signalled his world's surrender, but the call went unheard and unacknowledged by the Traitors.The signal was made again, this time on all available vox channels, but still the Traitor fleet in orbit did not answer. Again and again the signal was made, with increasingly frantic and shameful pleas for mercy, while all the time the fear built on the planet and the tension mounted to a breaking point as the solar hours wore on.While the Night Lords were the Legion most renowned for their use of terror as a weapon, the Sons of Horus were well-versed in its application, too. Below, within their fortified enclaves, the muster-barons who ran the great labour barracks began to turn on each other, and civil insurrection and infighting broke out. The tension became unbearable until one or several muster-barons turned upon Malthus Grange. The next transmission of surrender now carried images of his bullet-ridden corpse as a further offering to the Traitor fleet. It was only then that the Ikon answered.All across Moab pict-screens went live, showing the images of a savagely-armoured Astartes in a black-plumed, snarling-masked helm, all but unrecognisable as once one of the Emperor's finest warriors. They had made a beginning, the nameless captain of the Ikon told them, but it was not enough.Horus had sent him to save the people of Moab from the Emperor's lies, and from the weakness He had fostered, and the due payment for this boon was to serve Horus. But only the strong, only those who deserved to survive would live, and the blood of the weak would buy them that survival. "Kill in His name and live, or perish with your Emperor's name on your lips. It is for you to decide." What followed was unspeakable.Moab descended into anarchy. The streets ran with blood, cities were turned into open-topped slaughterhouses. A world murdered itself in fear of being destroyed by its new masters. Uncounted atrocities were committed in these days, and it was only several solar days later that the dark bulks of orbital lighters began to appear in Moab's skies and descended into its barrack-cities through the blood-reeking smoke that hung over them like a pall. Into their cavernous holds filed haggard, hollow-eyed men and women by the thousands, bound into Horus' service as foot-soldiers by a pact far darker than any sane mind could know or comprehend.The "Sorrow of Moab" is one of the darkest chapters in the already sombre history of the Horus Heresy. Despite the breakdown of astropathic communication, news of the horror quickly spread. The sombre tale of Moab's fate would cause much civil unrest on countless Imperial planets. Even in the distant Agathean Domain, the dire events of the Sorrow of Moab would spark insurrectionist and traitorous activity until the lauded former Imperial Commander Ireton MaSade rose to power and imposed planetary martial law.