Devastation of Baal - Desperate Measures: By the opening days of 999.M41, the Baal System had been reinforced like never before. Answering Commander Dante's call, one Blood Angels Successor Chapter after another arrived to lend much -- if not all -- of their strength to their primogenitors.Slab-sided defences were raised upon the blasted sands of Baal Prime and Baal Secundus, and even around the fortress-monastery of the Arx Angelicum on Baal itself. Fleets of cruisers and battle barges gathered in the void around Baal and its moons, their combined might enough to crush star systems and end worlds.Still, as deep-void auspex screens turned blood red with contact runes, and a ten-thousand-kilometere-wide tidal wave of chitin and flesh surged into the Baal System, it seemed unlikely that it would prove enough.With the Tyranids closing in, Commander Dante and his closest lieutenants authorised deeds that would have been unthinkable in brighter days. The Blood Angels' precious gene-seed reserves were removed from their storage crypts, packed carefully for transit under the watchful eyes of Sanguinary Priests, and then sent away on a swift starship with a hand-picked complement of guards.At the same time, millennia of tradition was cast aside as Blood Angels gunships gathered every viable Aspirant they could from amongst the nomadic tribes of Baal Prime and Baal Secundus. These youths were armed, and then ferried to the Arx Angelicum. There they formed defence garrisons whose strength was intended to augment that of Sanguinius' sons. At least forty thousand wide-eyed youths are gathered in this way, and told that any who survived the coming battle would surely prove their worthiness to join the Chapter's ranks.Of the remaining tribesmen of Baal little is said. Given what extra weapons and rations the Blood Angels can spare, they were left to hide or stand as they saw fit. Any Tyranids they killed would be fewer monstrosities to beset the Blood Angels and their successors, but the tribesmen were not expected to weather the horrors that followed -- and most did not.Knowing that the fate of his Chapter, and perhaps of the Imperium itself, would rest upon the defence of Baal, Dante had sent out the call to the Blood Angels' Successor Chapters, the so-called "Sanguinary Brotherhood," telling of the doom that was approaching the homeworld of their beloved progenitor, Sanguinius.All came to the Blood Angels' aid, from the ferocious Flesh Tearers to the noble Blood Drinkers, and even the savage, insular warriors of the Carmine Blades. Every single battle-brother would be vital in the upcoming war, for the oncoming Tyranid fleet was enormous, by far the largest Tyranid host ever recorded by the Imperium.Unwilling to cede void supremacy to the Tyranids of Hive Fleet Leviathan without a fight, Commander Dante ordered his naval vessels to strike at the enemy and slow their advance. Hundreds of thousands of bio-ships, in clusters so thick that the invasion fleet seemed to be one vast, many-limbed organism, surged towards Baal. The Blood Angels' own fleet met them head-on, its numbers bolstered by the presence of several spaceborne Successor Chapters.Across a hundred fronts, the red-armoured voidcraft of the Blood Angels and their successors struck at the fleshy Tyranid Hive Ships. Lances and gun decks split the darkness with their fury. Ruptured bio-ships tumbled away, slicks of ichor spilling from their sundered innards to freeze in the merciless void.The sky above Baal erupted in a violent firestorm as the rugged vessels of the Space Marines slammed their way into the midst of the approaching Tyranids, launching devastating broadsides and storms of nuclear-tipped warheads. Valorous as this naval action was, it was also hopeless.One by one, Space Marine battle barges and cruisers were isolated and overwhelmed, battered by organic missiles and enveloped by swarms of smaller bio-ships. Entering low orbit over Baal and its moons, the Leviathan's vessels began to disgorge clouds of spores and organic transports into the atmosphere.As the void battle raged overhead, the defenders of Baal awaited the first waves of Tyranids, taking up positions amidst Horus Heresy-era fortifications that had been unearthed and rebuilt by Chapter serfs and servitors. Baal and its twin moons had been transformed into killing fields, dotted with artillery redoubts, mine-laced choke points and criss-crossing fire zones.Dozens of Tyranid bio-ships were butchered, hundreds of thousands of warrior organisms slain before they ever saw the irradiated sands of Baal. Still the Blood Angels were driven back, every victory carrying its own butcher's bill in flaming hulks and dead battle-brothers.Soon enough the void war became unsustainable as more and more Tyranids emerged from the darkness in squamous waves. With their surviving voidcraft forced to fall back and harass the hive fleet's flanks, the Blood Angels now faced the full fury of the Tyranid invasion.On Baal, Baal Prime and Baal Secundus, aircraft-sized Mycetic Spores darkened the skies in their millions. The Shadow in the Warp settled like a shroud around the Baal System, choking off any further hope of reinforcement. The sons of Sanguinius stood alone in the face of the hurricane of death to come.