The first contact the Imperium of mankind had with the alien menace of the Tyranids took place on a little-known Imperial outpost in the Tyran system located on the southeastern fringes of the galaxy. The planet Tyran was an Adeptus Mechanicus way station for exploratory expeditions studying the virtually unknown sectors at the edge of the galaxy. Because of its isolation the base was well protected despite their small size and boasted an Astropath for communication with the Earth, over 60,000 light years away.

The first disquieting reports from Tyran told of a number of ravaged worlds, which lay at the very edge of intergalactic space. In ancient surveys these particular planets had been logged as supporting life but more recent expeditions reported them to be bare, airless rocks. At first nothing untoward was apparent: the earlier surveys were hundreds, sometimes thousands, of years old and inaccuracies were not uncommon.

As time passed the Technomagi found that worlds which were known to have thriving ecosystems had been transformed into barren planetoids. Investigation teams could find no discernible cause for the phenomena and the reports filed with the Explorator General received little attention. The planets in question had supported no sentient life forms and lay thousands of light years from the nearest human-colonized systems. In a galaxy of a billion worlds such mysteries abounded, so for a time the information languished in the hundreds of miles of databanks that form the archives of the Administratum on Earth.

As the Tyran outpost dutifully continued to file reports of dead worlds the growing body of evidence attracted the attention of an organization that abhors mysteries and unexplained phenomena: the Inquisition. Inquisitor Kryptman, well respected for his far-sighted condemnation of the Macharian Heresies, began to ask probing questions about events in the distant southeast. The Adepts of the Explorator's office could offer little additional information but as soon as Inquisitor Kryptman compiled and analyzed the reports on the extinct worlds it became apparent that the phenomenon exhibited a distinct pattern, and was encroaching ever deeper into the galactic rim.

The Inquisitor presented his findings to the council of the Inquisition and received dispensation to commandeer a ship to travel to the eastern fringe and uncover more data. But even as the Inquisitor's ship was churning through the warp Tyran came under attack.

The Tyran Primus base lay in the midst of Tyran's great world-spanning oceans, dug into an island that was the very tip of a chain of ancient volcanoes. The oceans of Tyran covered over 80% of the world's surface and were home to a dizzying array of marine life ranging from the small and innocuous scuttlefish to the highly dangerous 200-meter long kraken. The base itself was fortified to resist violent storms and the attentions of the voracious oceanic life forms. Tyran Primus also had four giant defense lasers in armored silos for defense against marauding alien spacecraft and any unknown monstrosities lurking in the deep oceanic abyss.

Over four hundred personnel manned the base Administratum scribes, Explorators, Adeptus Mechanicus Genetors, Engineers, Lexmechanics, their entourage Servitors and a single Astropath. They were under the command of Magos Varnak. a member of the ruling caste the Cult Mechanicus. Explorator ships passed through the Tyran system to collect supplies and deliver reports every three to six months. The last ship to depart was the Investigation, destined to survey worlds on the Eastern Fringe though Varnak feared all he would receive were further reports of extinct planets.

Over a month after the departure of the Investigation Tyran Primus detected a cloud of close to a thousand unidentified objects entering the Tyran star system. After initial studies revealed the cloud was made up of neither spacecraft n debris Magos Varnak piloted one of the station's small system ships towards the cloud to investigate further. When approached, the ship came under attack by unknown object almost immediately. Magos Varnak was injured, several oft crew were killed and the ship itself was so badly crippled barely survived the journey back to Tyran. As he recovered from his injuries Varnak grimly ordered the base to alert status and armed the Servitors who would act as the first line defense if there were an invasion.

A week later the first attacks began on the base. The storm-wracked skies of Tyran were split again and again by the blinding flash of the defense lasers as they strove to drive t] attackers away. Bolts of laser energy capable of melting through whole city blocks lanced into space as projectiles launched by the enemy above smashed down on the base. Silo 2 was shaken and cracked by several hits but the chants and ceremonies of the Tech Priests kept it firing.

The uneven battle raged on for an hour or more as the bra laser crews blasted at the hundreds of invaders around Tyran before, amazingly, the enemy simply withdrew. Varnak sent his three remaining system ships in pursuit of the foe. They added to the destruction already wrought by the ground-bas lasers and confirmed Varnak's earlier observations of the attackers. The objects appeared to be creatures of alien origin vast armored organisms with thick carapaces that were apparently fully adapted for life in space.

The system ships were quickly crippled or destroyed by the bio-ships and Magos Varnak was informed that the defenses of Tyran had damaged or destroyed only a dozen creatures out of a swarm of close to a thousand. He was forced to conclusion that should the invaders attack again and with greater vigor the base on Tyran was doomed. Escape was impossible. All that remained was to try and warn the Imperium before selling themselves as dearly as possible.

But the Astropath could broadcast no messages. The disruptions caused in the warp by the creatures' arrival made it impossible to use astrotelepathy. In a few hours or days the warp might clear but for the moment Tyran was completely cut off. To preserve what knowledge they had Varnak ordered a data codex to be formed of all the information gathered about the invaders. The data codex would be set to record the fate of the base until it was sealed at a signal from Varnak's control pulpit and dropped into a 3,000 meter deep bore shaft beneath the base. Even as the codex was being prepared the aliens moved in to attack positions once more.

As they came within laser range the invaders released thousands of pods above the planet. The pods fell toward Tyran in tight clusters and did not break up as they hit the atmosphere. Though the laser defences destroyed any pods which would have impacted on the base many more fell into the sea around it. To enter the sea was death for a human yet the aliens could be seen approaching the base on sonar scan. The seas thrashed and boiled as more aliens emerged from their pods and hacked their way through the voracious native beasts that swarmed around them.

Defense laser fire ripped into the bio-ships as they began an intense bombardment of the base. Several of the creatures fell burning into the atmosphere but the bombardment continued. Hissing acids ate through the armoured laser silos and one by one they were silenced. Magos Varnak watched the advance of the aliens on the crystal screens of the sacristy. The creatures were upright and six-limbed, clawed and fanged like fiends. The scattered defensive fire ricocheted off their thick hides and heavy carapaces like hailstones.

The aliens attacked the south dock and smashed their way through the electro field and armourplas shutters as if they were paper and glass. Servitors guarding the dock fought back with flamers and the first invaders through the breach were slain or driven back hissing their defiance. But other creatures, screaming giants with arms like great scythes, waded forward and Magos Varnak watched in horror as they shrugged off the napalm fires and hacked their way through the Servitors as if they were made of straw.

In an instant the enemy were through the dock and spreading through the base, destroying everything they found. Magos Varnak's finger hovered over the switch that would send the data codex plummeting into the depths. Every moment might give some additional insight into the enemy, but every moment brought the fighting closer to the sacristy. Smaller, scuttling creatures appeared in the enemy ranks and began to cast constricting webs over the Servitors and Tech-Priests as they fought in the corridors.

Varnak looked to the station Astropath and both understood that they could not allow themselves to be captured by this new and terrible alien race. Varnak released the codex and descended into the reactor chamber to set the station destruct sequence. Even as he completed his prayer the doors of the sacristy were buckling and tearing before the fury of the assault from outside, and with only seconds remaining Magos Varnak struck the sacred rune of ending upon the power altar.

Earth received one final, garbled message from Tyran. On the wings of death came a dire prophecy of doom and a mental image of the skies over Tyran turned black with swarming monsters. From the world of Tyran the invaders acquired a name at last --