Drop Site Massacre - Treachery Most Foul: The second wave of "Loyalist" Space Marine Legions descended upon the landing zone on the northern edge of the Urgall Depression. Hundreds of Stormbirds and Thunderhawks roared towards the surface, their armoured hulls gleaming as the power of another four Astartes Legions arrived on Istvaan V. Yet the Space Marine Legions of the reserve were no longer loyal to the Emperor, having already secretly sworn themselves to Chaos and the cause of Horus. The Night Lords of Konrad Curze, the Iron Warriors of Perturabo, the Word Bearers of Lorgar Aurelian, and the Alpha Legion of Alpharius represented a force larger than that which had first begun the assault on Istvaan V. The secret Traitor Legions mustered in the landing zone, armed and ready for battle, unbloodied and fresh.The Iron Warriors had claimed the highest ground, taking the Loyalist landing site with all the appearance of reinforcing it through the erection of prefabricated plasteel bunkers. Bulk landers dropped the needed battlefield architecture: dense metal frames fell from the cargo claws of carrier ships at low altitude, and as the platforms crashed and embedded themselves in the ground, the craftsmen-warriors of the IV Legion worked, affixed, bolted and constructed them into hastily-rising firebases. Turrets rose from their protective housing in the hundreds, while hordes of lobotomised Servitors trundled from the holds of Iron Warriors troopships, single-minded in their intent to link with the weapons systems' interfaces.The Word Bearers bolstered their brother Legions on one flank of the Urgall Depression while the Night Lords took positions on the opposite side. Down the line, past the mounting masses of Iron Warriors battle tanks and assembling Astartes, First Captain Sevatar of the Night Lords and his 1st Company elite, the Atramentar, took up defensive positions. Both the Word Bearers and the Night Lords were to be the anvil, while the Iron Warriors would be the hammer yet to fall. The enemy would stagger back to them, exhausted, clutching empty Bolters and broken blades, believing their presence to be a reprieve.It is held by some sources that, upon the arrival of the four fresh Legions, Corax, the usually taciturn Primarch of the Raven Guard, was the first to call for a withdrawal for those fighting in favour of the newcomers to take the lead. His Legion had suffered severely in the battle, as had all the combatants, and he had no desire to waste further lives in pointless attrition, where stronger forces, yet un-bloodied might take to the fore. Vulkan was also in favour of consolidation, his Legion having seen some of the most relentless and savage fighting against the Death Guard. The dark weapons of the XIVth Legion had inflicted a great many casualties and almost all of Vulkan's warriors were counted among the fighting wounded, their munitions all but spent.Dragging their wounded and dead behind them, Corax and Vulkan led their forces back to the drop site to regroup and to allow the warriors of their recently arrived brother Primarchs of the second wave a measure of the glory in defeating Horus. Though they voxed hails requesting medical aid and supply, the line of newly-arrived Astartes atop the northern ridge remained grimly silent as the exhausted warriors of the Raven Guard and Salamanders came to within a hundred metres of their allies. It was then that Horus revealed his perfidy and sprung his lethal trap.Inside the black alien fortress where Horus had made his lair, a lone flare shot skyward, exploding in a hellish red glow that lit the battlefield below. The fire of betrayal roared from the barrels of a thousand guns, as the second wave of Astartes revealed where their true loyalties now lay. The Loyalists' supposed "allies" opened fire upon the Salamanders and Raven Guard, killing hundreds in the fury of the first few moments, hundreds more in the seconds following, as volley after volley of Bolter fire and missiles scythed through their unsuspecting ranks.Even as terrifying carnage was being wreaked upon the Loyalists below, the retreating forces of the Warmaster turned and brought their weapons to bear on the enemy warriors within their midst. Hundreds of World Eaters, Sons of Horus and Death Guard Astartes fell upon the veteran companies of the Iron Hands, and though the warriors of the X Legion continued to fight gallantly, they were hopelessly outnumbered and would soon be hacked to pieces. The Iron Hands had damned themselves by remaining in the field instead of retreating like their fellows.The Raven Guard's front ranks went down as if scythed, harvested in a spilling line of detonating Bolter shells, shattered armour and puffs of bloody mist. Black-armoured Astartes tumbled to their hands and knees, only to be cut down by the sustained volley, finishing those who fell beneath the initial storm of head- and chest-shots. Seconds after the first chatter of Bolters, achingly bright laser beams slashed from behind the Word Bearers as the cannon mounts of Land Raiders, Predators and defensive bastion turrets gouged through the Raven Guard and the ground they stood upon.The Iron Warriors and Word Bearers kept reloading, opening fire again, hurling grenades and then preparing to fall back. The Word Bearers Legion had taken up landing positions on the west of the field, ready to sweep down and engage the Raven Guard from the flank. Three figures stood atop the roof of an ornate command tank, the Land Raider’s bronze and grey armour decked out with flapping banners and etched with fingernail-fine scripture over every visible surface. Kor Phaeron, Master of the Faith, watched the distant dropsite through a desperate squint. The Word Bearers First Chaplain Erebus, the architect of Horus' fall to Chaos, stood at his side.Lorgar towered above both of them, but had no attention to spare for the treacherous opening salvoes against the warriors of the Raven Guard and Salamanders Legions. He stared into the battlefield's heart, his eyes wide even in the wind, his lips gently parted as he watched his brothers killing each other. Fulgrim and Ferrus, the fading sunlight flaring from the edges of their swinging weapons. The wind stole the clash and clang of their parries, but even in silence the duel was beyond captivating. No human senses save those as acute as a Primarch's could have followed such instant, liquid movements.The perfection of it all almost brought a smile to Lorgar's lips. As the Primarch watched his two brothers engaged in their furious duel, he recalled a time long before when Ferrus had presented him with a weapon he had personally forged. Ferrus had crafted the fine crozius-maul, Illuminarum, as thanks for the reinforcement of the Xth Legion by the Emperor's Children at Galadon Secondus. Snapping back to reality, the seed of doubt crept into Lorgar as he played witness to the slaughter around him. But with the prodding and reassurance of his adopted father Kor Phaeron, Lorgar ordered his Word Bearers to attack.At point-blank range the unsuspecting Legionaries of the Salamanders and the Raven Guard were cut down by the hundred by those they thought their brothers. Battered tanks and Dreadnoughts that had weathered the storm of three solar hours of the most hellish combat the Legiones Astartes had ever seen were caught in a blizzard of missile and Lascannon fire from those they expected to be allies, their explosive pyres igniting in droves up and down the Loyalist battle line.Night Lords gunships raked across the sky, raining down phosphex and cluster munitions, screaming Raptors following in their wake, and without warning the Alpha Legion were in among the hastily set-up Apothecarion stations of the rear echelon, murdering with ruthless efficiency, while their fast-moving armour and mechanised squads encircled the Salamanders before slicing into them with a surgeon's precision. From behind the steel-clad emplacements of the Iron Warriors, the vaunted artillery of the Stor-Bezashk spoke, their deadly Scorpius Pattern Whirlwinds and Minotaur siege guns laying waste to the stunned Imperial Army battalions and ravaging the first wave's landing zones, while their Cerberus and Typhon tanks advanced to rip apart the Imperial Army's super-heavy tanks at close-quarters.