Tyran - Invasion: Tyran's planetary Defence Lasers opened fire on the foe the moment the first alien bio-ships entered orbit over the Ocean World. For more than a solar hour, the perpetually stormy skies of Tyran were ruptured again and again by coloured blasts of coherent light as the base's gunners desperately sought to drive back the descending xenos invaders.Then, just as the Defence Lasers had begun to glow white hot and overheat from the sheer number of targets, the invaders suddenly withdrew.Buoyed by overconfidence in his own forces and ignorance of the true scope of the threat, Magos Varnak ordered his small fleet of Imperial Navy cruisers to harry the withdrawing bio-ships, but this strategy proved to be mistaken.After penetrating the spore cloud that masked the sheer size of the approaching alien fleet, the pursuing Imperial starships discovered that less than a dozen of the strange organic spacecraft had been destroyed out of the thousands present in the fleet that had entered the Tyran System.Having successfully lured the Imperial cruisers away from the support of the planet's Defence Laser emplacements, the bio-ships suddenly changed direction and fell upon the Imperial vessels like hungry sharks.The Emperor's Fist was the first Imperial starship destroyed, its hull shredded by a voracious swarm of organisms vomited forth by a much smaller vessel. The Righteous Destiny did not last much longer as a cluster of grasping tentacles dragged it into the gaping maw of a Hive Ship.Only the Sword of Warriors lasted long enough to transmit a warning by Vox to Tyran. Before the message was completed, leech-like pseudopods gnawed through the starship's adamantium hull plates and unleashed a horde of vicious Genestealers onto the spacecraft's bridge and lower decks. The entire crew was slaughtered within minutes and the Cruiser was left to drift in space unmanned, its precious biomatter already dissolved into the Hive Fleet's reserve stocks.With the Imperial cruisers lost, the hive fleet then returned into orbit of Tyran and this time the Imperial defences proved inadequate. Thousands of Mycetic Spores hurtled down onto the world, and though the Defence Lasers managed to still destroy many of the lethal pods, countless more crashed into the stormy seas.All around the Imperial outpost, the waters boiled as the invaders burst from the spores and tore their way through the powerful maritime predators of Tyran's oceans, who were no match for the savagery of the Tyranids.Then the xenos scaled the walls of the Imperial outpost. At first, disciplined volleys of laser fire from the Imperial Guardsmen managed to drive the voracious creatures back, as amongst their numbers were veteran Guardsmen from the jungle-covered Death World of Catachan, long-used to battling the similar monstrous fauna of their own homeworld. The Guardsmen fought through the constant, pouring rain and their firepower scythed out massive holes within the alien line.The hides of the smaller bioforms offered little protection from concentrated laser fire and were no match at all for the Autocannons of the interceptor grid erected around the base.Wave after wave of Hormagaunts and Genestealers were torn apart and their corpses began to choke the carefully laid-out killing zones that lay between the outpost's bastions. Thunderbolt fighters soared through the skies above the base, destroying any incoming spores with precision fire before darting away to find new targets. And there were always more targets...But the Imperial defence began to crack when the northern planetary Defence Laser finally fell silent. Thousands of Gargoyles had thrown themselves on the Hive Mind's order into its barrel, clogging the gigantic beam projectors with their own blackened bodies. Moments later the eastern planetary Defence Laser was destroyed when a Carnifex penetrated its steel walls and ripped apart the massive weapon's coolant lines.Despite their valiant efforts, the Thunderbolts eventually fell from the skies, their engines choked by spores or their pilots torn shrieking from their cockpits by Harpies. As the Imperial defence network collapsed, the Mycetic Spores began to fall onto the outpost itself.