Honoured Lords, it is with the utmost vigour that I urge you to consider the contents of this document vital to the survival of our beloved Imperium. The words it contains impart information gleaned at terrible cost from the defeat of the Tyranid Hive Fleet Behemoth in the Ultima Segmentum. The stellar realm of Ultramar, controlled by the Ultramarines Chapter of Space Marines, bore the brunt of the Tyranid fleet and it is in no small measure thanks to the dedication, bravery and sacrifice of the Ultramarines that so much was learned and the invasion halted. A leading authority on the Tyranid race, the learned Inquisitor Kryptman saw at first hand the full horror of these aliens and he realised that the threat posed by these monstrous extragalactic creatures cannot and must not be underestimated. The knowledge he and others gained in the fight against Hive Fleet Behemoth prompts me to compile the surviving records from those dark times as a warning against future lapses in vigilance.

As a prelude to this report 1 have attached the following extract from the Explorator files authored by Explorator Magos Dana Aquila.

Prior to the Tyranid attack on Ultramar, the Adeptus Mechanicus filed this report on the home worlds of the Adeptus Astartes:

Ref: 704/89: In my time researching the varied and multitudinous home worlds & bases of the Adeptus Astartes, it has been a constant struggle to obtain the cooperation of the Chapter Masters. Information to date has been scant and based largely on hearsay from other units fighting alongside them. It was therefore with extreme surprise that I was extended every courtesy by Marneus Calgar, Master of the Ultramarines Chapter when I submitted my request for information regarding the realm of Ultramar.

Situated deep in the galactic south-east in the Ultima Segmentum, Ultramar is unique amongst all the Chapter headquarters of Space Marines, in that while most Chapters operate from asteroid bases, lonely fortress monasteries and isolated worlds, the Ultramarines control no fewer than eight nearby systems from their home world of Macragge. Each of these worlds has its own government, armed forces and individual cultures, but all are utterly loyal to the Ultramarines Chapter. Initially I was highly suspicious of the manner in which the Chapter has extended its control over such an unusually high number of planets. Indeed when I questioned the people of these worlds in regards to this, I was met with stony silences if not downright hostility. Such 'empire building' would be frowned upon under conventional Imperial doctrine, but my investigations have convinced me that no such desire exists within the Ultramarines.

The worlds surrounding Macragge are largely industrial in nature, though they are not polluted, poison choked wastelands such as Necromunda and Armageddon. I firmly believe that this is largely due to the organisational skills and far-sightedness of the Chapter's legendary Primarch Roboute Guilliman. Under his guidance these worlds were revolutionised into prosperous, productive planets where honest toil and virtue were rewarded and the populace flourished like never before. I found the inhabitants of these worlds to be industrious, disciplined and intensely loyal Imperial citizens.

Unlike other planets of the Imperium, these worlds are not required to pay Imperial tithes. When looking to their defence each world can rely on the protection of the Ultramarines, but, as would be expected, each one raises its own troops. These worlds are not required to levy troops for the Imperial Guard, but such is the prosperity and highly organised nature of the Ultramarines realm that it maintains hundreds of regiments which can fight as and when required throughout the galaxy. As well as their own defence, the worlds of Ultramar provide recruits for the Ultramarines and it is a source of fierce pride when a particular family can point to an ancestor who became a Space Marine.

Some twelve millennia ago, in the glorious days of the Emperor's Great Crusade, the worlds surrounding Macragge provided the Chapter with hundreds of new recruits, raw materials, supplies and all manner of support. Following the break up of the old Space Marine Legions into the Chapters we recognise today, this tradition has continued throughout the millennia. Close ties have been maintained between Macragge and its surrounding planets, and it is not surprising that many of these worlds share a commonality in language, culture, architecture and governmental styles.

It should not be thought that these worlds are identical. Each has its own particular character and distinctiveness which is dealt with in a later treatise. I shall confine myself to only the most general traits of each planet for now.

Macragge is a rocky world, protected by numerous orbital defences and two vast polar defence grids. It is on this planet, in the harsh and unforgiving mountains that the Ultramarines have their fortress, housing the shrine of the Primarch himself. Here the legendary Primarch's body is held within a stasis field and is a place of great pilgrimage for all loyal citizens of the Imperium. I myself had occasion to visit this shrine and can honestly say that I was deeply moved by the experience. Truly was the Primarch a giant amongst men.

Talassar is a turbulent planet of tempests and violent seas, with but a single continent named Glaudor that saw the defeat of the base Orks in battle following the Great Betrayal. In contrast, the three worlds of Quintarn, Tarentus and Masali orbit a common centre of gravity and outside the huge, enclosed agri-cities are desolate and arid. Wind traps collect water for these domed cities that protect verdant greenery and hundreds of square miles of agricultural land. Calth's populace live below the planet's surface, far from the deadly rays of its blue sun. Vast subterranean caverns, so fresh and spacious as to make a man forget that he is underground, honeycomb the planet's crust and though the planet, like all others in Ultramar, is self-sufficient, a great deal of food is shipped in from nearby Iax. The planet's shipyards are justly famous and construct a sizeable proportion of the ships in the Ultramarines fleet as well as those used by other arms of the Imperium.

Both Iax and Espandor are sparsely populated worlds towards the edge of Ultramar. Iax is a model of how an agri-world should be managed and is one of the most productive worlds in the Imperium. Other Imperial commanders have been settled when traders were should take note! Espandor is primarily blown off course by a warp storm during composed of forests and is rumoured to the Age of Strife.

The crowning glory of Ultramar is without doubt, Prandium. Its climate is temperate and the natural beauty of its geography mark it as one of the most exquisite planets I have ever had the good fortune to visit. My duties permitting I shall certainly return to the realm of the Ultramarines again.

Scribe's Note: Prandium was destroyed in the First Tyrannic War, stripped bare by Hive Fleet Behemoth.

Initial investigations into the emerging threat were undertaken by Inquisitor Kryptman.

The first recorded contact with these aliens was at the Tyran Explorator Base, in the farthest reaches of the southeastern arm of the galaxy. It is from this world that they finally acquired a name - Tyranids. Reports of devastated worlds and planets laid waste were logged and filed by the Explorator Base for many years until I began to see an underlying pattern emerging. I took ship to the Tyran outpost to further investigate these disturbing reports. During the journey I received a garbled report from Tyran, forwarded by Astropaths on Earth. A terrible vision of the sky turned black by monstrous swarms of hellish creatures. It was a dire warning of things to come.

When my vessel arrived in the Tyran system, the navigational auguries could not at first divine the location of the Imperial outpost. Where I had expected to find a world covered by oceans, I instead found an airless dead rock, stripped bare of all life. A weak transponder signal was the only sign that this world had once been Tyran. I led an exploration team to the surface and discovered no survivors, no bodies and no trace of the planet's attackers. Determined to uncover the truth of what had occurred on Tyran, I refused to give up and at last discovered a data codex, buried in a deep bore shaft some 3,000 metres below the planet's surface.

The things I saw on that codex chilled my blood like never before and my admiration for Magos Varnak, Tyran's commander, grew as I learned how he and his men had fought to the last against this terrifying foe before sealing the codex away so that others might learn from their deaths. Armed with this information I left dead Tyran and set out to warn the Imperium of this deadly new enemy only to find that the psychic wake caused by this alien fleet had disrupted the warp to such a degree that communication was impossible. I immediately set course for the Thandros telepathica booster. By the time I arrived at Thandros, the Tyranids had already attacked and once more there were no survivors. I made one discovery of note aboard the telepathica matrix. In the crew quarters I chanced upon a translucent, filmy material, like shed skin, and a colourless ooze dripping from a bulkhead. Samples of these were taken and although it was clear they were of alien origin, nothing more could be discerned without proper laboratoria facilities. The adepts of the Machine God aboard my ship were able to salvage the telepathica matrix (obviously the Tyranids had no use for such a device) and my Astropath was finally able to pass word of the invaders and my discoveries to the Imperium. In return I received orders to travel to Macragge, planet of the Ultramarines in the realm of Ultramar.

Events had been set in motion even before my ship had arrived and a dozen vessels already hung in orbit around Macragge. Mile long Space Marine battle barges dwarfed strike cruisers arriving from the furthest reaches of Ultramar and every day more ships arrived from the warp. The static orbital defences were also impressive, ringing Macragge with a cordon of fire that, against a conventional opponent, would prove impossible to breach. It remained to be seen how they would fare against the Tyranids. To further augment the system defences, a battlefleet from the Segmentum Tempestus sector base at Bakka was dispatched. I prayed that it would arrive in time.

On Macragge I met with Marneus Calgar, Chapter Master of the Ultramarines and even after I had appraised him of the horrors approaching his realm, he was unperturbed. He merely stated that the men ot Ultramar would serve the Emperor until their last breath had been crushed from their bodies. I must confess that I found Calgar to be a man of great courage and could hope for no one better to lead the defence of Macragge.

Further information had come to light with a survivor's eye witness account of a Tyranid attack on the stellar liner Galacris Luxor and the discovery of a complete Tyranid organism aboard the derelict freighter Hammer of Foes, Adeptus Mechanicus Genetors at the Inquisition fortress of Talasa Prime had deduced that while the creature was definitely of Tyranid origin, it was not of the same force that had attacked Tyran. The implications of this were truly terrifying. It was now clear to us that there were in fact two Tyranid fleets, one leapfrogging the other in their consumption of worlds.

A month later, with no sign yet of the Segmenrum Tempestus battlefleet, the Tyranids attacked Macragge.

At the forefront of the initial space battles, the captain of the Vae Victus witnessed much that will be of interest to starship captains who may soon have to face these aliens.

<<295 18:45> Emperor's mercy, what are these things? We are but ants attacking a Grox against them! Every attack we make is swept aside. Gigantic craft, like disgusting sea dwelling monsters with curled shells and questing tentacles are surrounded by tiny, darting... shapeless things that I cannot find the words to describe. Each volley of torpedoes we fire is intercepted by swarms of these creatures and our weapon decks are befouled by them.>

<<296/5:30> Whole squadrons of fighters and bombers are destroyed in a heartbeat and while our lasers burn gaping tears in the chitinous hides of these beasts we cannot bring enough fire to bear on any one bio-ship to count. I saw the Imperator Rex pass too close to one of the hulking craft, becoming ensnared by some loathsome organ that dragged the ship into the embrace of thousands of tearing claws and scything blades that broke the mighty vessel in two. For every one of the smaller craft we destroy, a hundred times that number are vomited from the belly of the larger bio-ships. We must retreat back to Macragge, we cannot fight in this manner and survive. To die this way is no service to the Emperor and we may yet find a way to fight this foe more effectively another day.>

<<298/03:23> We are now committed on a perilous course of action. With no sign of the Tempestus battlefleet, Lord Calgar has ordered the fleet to disengage and move outsystem in a bid to draw the aliens onto the orbital and polar defences of Macragge. With the Tyranid fleet spread out around the planet he believes we may yet be able to cause enough damage to stop the aliens. May the Emperor prove him right, for we are lost if he is not.>

<<298/06:23> The hive fleet scatters before us! As though guided by the Emperor's own hand our divine weaponry cuts a swathe through the alien vessels. Spread out, they are much more vulnerable to our righteous fire and our manifest supremacy is now becoming clear.>

<<300/11:59> We have to give our fighters more time! Concentrate all firepower on the main hive ship! It is almost ready to go! See how it spills it's lifeblood into space. Kill it, kill it now! Reload damn you! Full spread of torpedoes. Fire! Fire! Fire!>

<<300/14:59> There! You see it perish? Our fighters deliver the killing blow and it dies. Such is the fate of all invaders! Wait... the other ships, they drift now as though they cannot function without the guidance of the larger ships. We must strike while we have the advantage. Launch all remaining fighters and bombers, prepare to attack! We shall reap a bloody harvest this day!>

<<300/17:11> Hundreds of the Tyranid ships are dying. Without the main hive ship to direct their attacks, they fight in an uncoordinated manner and are easy meat for my gunners. Many of the hive ships have pulled back behind a screen of the smaller ships and are disgorging what appears to be a hail of spore-like organisms above the polar regions of the planet. What exactly they are, our divination auguries cannot tell, but I fear they must be some new and terrible weapon. My prayers are with the defenders on the planet's surface.>

<<301/16:11> The Tyranids are withdrawing! Their battered ships fall back before us. The order has come to give pursuit and eradicate them. Though we are outnumbered we shall prevail and destroy the Tyranids. Through the flames of perdition and for the Emperor we shall follow the aliens to the edge of the galaxy if need be! The victory shall be ours.>

This fragment of a soldier's personal journal was discovered on his dismembered body within the southern polar defence fortress.

Day 26: I was looking along the barrel of my lasgun, trying to keep my breathing even. 1 knew I mustn't show any fear in front of the men. I couldn't see anything yet, but that didn't make me feel any better. Worse in fact. I knew the aliens were out there; we'd all watched as millions of spores dropped from space and turned day into night. The sky had burned with defence laser fire, but the massive guns couldn't hope to down all of them.

The sun was low and you had to squint against the glare of sunlight on snow to make sure you didn't go snow-blind. I checked left and right along our position. Thousands of fellow Defence Auxillia troops manned the firing steps of the trenches, our strength bolstered by the presence of veteran Space Marines from the Ultramarines 1st Company. I felt immensely proud to be fighting alongside them. Surely whatever was coming could not stand before such legendary warriors. How little I knew.

The ground shook as the Titans of the Legio Praetor shifted position, bracing their legs into a firing stance. The enormous machines must have seen something I couldn't. The air around them shimmered as their void shields powered up and their huge weapons, locked in place. I peered out onto the ice plains again and in the distance saw the Tyranid swarm for the first time. On the horizon 1 saw a shifting, blurred motion, a swarm of creatures too numerous to count speeding across the ice fields towards us. A low, buzzing, skittering noise came from the approaching horde, insistent and grating on the nerves. I grabbed a pair of magnoculars from Trooper Park and trained them on the horizon, zooming in on the mass of creatures.

I'm not ashamed to say that my knees sagged and my heart skipped a beat as I saw the horrors that scuttled, leapt and thundered their way towards us. Beasts that defied any classification of form swarmed forwards, stretching as far as the eye could see in all directions. Shadowy forms, lost in a haze of ice crystals came after the smaller creatures, massively built with scything legs and jaws as big as dropships. A suffocating fear rose in me, paralysing my limbs and turning my blood to ice. It seemed to me that there was no way we could fight these creatures. Nobody could stand against these numbers, I had to get away...

Then from amongst the lines of Defence Auxillia, a Space Marine Chaplain, as if sensing the beginnings of panic amongst us, began to sing the Battle Hymn of the Imperium in a loud, clear voice. Amplifiers in his suit of powered armour carried his voice across the trenches. Along the line, Space Marines and Defence Auxillia troopers began to join in and, like water poured on a fire, the mounting panic was quelled. A resolute determination filled me and I could feel it spread to all the men of Macragge who stood shoulder to shoulder in the trenches.

A deafening salvo of shells and rockets shrieked overhead and impacted square in the centre of the alien horde, throwing up great chunks of ice and broken alien bodies. The whole swarm was momentarily obscured as every Titan and artillery piece fired and engulfed the aliens in fire and smoke. A huge cheer went up from our line, but died just as quickly as the aliens came on undaunted and apparently undiminished.

Heavy weapon fire tore huge holes in the alien charge as the range closed still further and I shouldered my rifle, watching the range counter on my rifle's scope unwind impossibly quickly. The numbers flashed green and 1 pulled the trigger, a powerful blast of laser energy burning a hole in one of the smaller aliens. Their speed was unbelievable and I only managed to fire about three shots before they smashed into our line.

Then they were amongst the trenches. Sickle armed beasts with sinewy arms, slicing and eviscerating. Six limbed creatures with slashing sword-like claws and whips that coruscated with a crackling purple energy. Shark-faced living battering rams with giant razor claws and screaming roars. Blood splashed bright on the snow, armour cut through like paper and men running insane with fear. The sky darkened with drooling creatures borne aloft on leathery wings, vomiting corrosive gobs of acidic fire.

I fought with my bayonet, hacking and killing. I ducked as a snarling creature came at me, slashing with razor sharp claws likes scythes. I desperately parried and stumbled backwards, falling to the trench floor. The beast hissed, ready to pounce and disembowel me. Powerful muscles uncoiled as it launched itself at me. 1 screamed, thinking that this was my time to die when a swipe from a Space Marine's power sword chopped the creature in two. Its severed thorax slammed into my chest and still its fanged maw sought to bite me. I pushed the bloody mess away, repulsed beyond words. The Ultramarines Space Marine who had saved me dragged me to my feet, thrust me back towards the firing step and moved on, firing his bolter at the aliens. I was terrified, but damn it, I'm a soldier of the Emperor and began firing into the swarm once more. Soon I established a rhythm, firing until the rifle's energy pack was dry, slamming a fresh clip in and repeating the process. Wave after wave of the aliens broke themselves against our defences and how long we fought for, I honestly couldn't say. My vision blurred with fatigue and snow-blindness, but it didn't matter, there were too many to miss. I fired mechanically, any sense of my surroundings dulled by sheer terror.

Suddenly it was over. Hissing defiance, the aliens pulled back out of our weapons' range, leaving huge mounds of corpses piled high against the defence line. A cheer went up from the Auxillia troops, a cheer that came not from a sense of victory, but the simple elation of survival. A wailing siren from the base loudspeakers sounded the fall back signal and I cast my gaze around the trenches. I fell to my knees retching, overcome by the sheer scale of the slaughter Thousands were dead, ripped to shreds and huge gaps had been torn in our line. If the aliens attacked this position again, there would be no way of holding it. I gathered up my remaining energy packs and joined the surviving defence troopers and Space Marines streaming back to the secondary line of bunkers and trenches. As I ran, I vowed that I would make these abominations pay a fearsome toll in blood for every yard they dared to advance.

The Tyrarads use bio-constructs of comparable size to the God-Machines employed by our own holy Titan Legions. This extract demonstrates the lethality of these abominations in graphic detail.

03:34 hours: Channel 564/M3.
Moderati! I read a jam on the carapace rocket launchers! Fix it immediately! Salvo on grid reference 236 alpha, 303 omega. Maximum burst. All other weapons cycle auto loaders and continue to fire on sectors Tertion and Primus. Watch for overheating! Deus lux! Look at the size of that thing! It's bigger than an Imperator Titan! By the Emperor's holy rule, we cannot suffer such a thing to live. Moderati Araya, concentrate your mega-cannon fire on that beast to our forward quarter!

03:58 hours: Channel 564/M3.
Damn it, I said to watch for overheats Moderati Decius! Assign yourself one hour in the shriving chamber upon this battle's conclusion. Princeps Calvin to Engineer Calder give me striding speed, we take the fight to the alien scum! I see fluid leaking from its hide. Ready chain fist generators! And someone clear the smaller creatures from the legs of my titan! They slow us down...

04:01 hours: Channel 564/lvlЗ.
Death to all enemies of the Emperor! Free up those turbo lasers Moderati Decius, burn through the tentacles! Get that chain fist free! Stepping back. No! We cannot move! Engineer Calder what the hell are you doing down there? Give me power to the legs! What do you mean we have power? Then why are we not moving? Imperator! The joints are clogged with the corpses of the smaller beasts... Emperor save us!

04:24 hours: Channel 525/M6.
Left arm gone. Moderati Araya dead and Moderati Decius mortally wounded. The beast is upon us and I commend my soul and those of my crew to our beloved Emperor! The beast has destroyed us! Like swarms of ants they climb the body of the God Machine and tear me down. I see them now at the armoured glass of my control centre, clawing their way in. They will tear me apart. They will not take the Semper Sanctus from me I swear! Activation of reactor overload. Princeps Sidarius Calvin. Authorisation code [classified]. May the Emperor and the Machine God forgive me for what I do now. Finis Rerum!

Scribe's Note: The Semper Sanctus was destroyed in a self-initiated reactor overload that destroyed the Titan and the Tyranid construct now classified as a Hierophant bio-Titan.

Compiled from the surviving powered armour suit logs, the following text tells of the destruction of the Ultramarines 1st Company.

"And thus were the battle brothers of 1st Company tasked with the final defence against the Tyranids of Hive Fleet Behemoth. The ferocity of the Tyranids was unmatched save by the determination of the Company to defeat them. Even those brothers honoured wit Tactical Dreadnought armour could n: stand against the foe in close comba-Only the righteous fire from storm bolters and heavy flamers kept the foe at bay. Multi-limbed creatures with claws and swords of chitin moved like quicksilver and their blades ripped open armour and bodies with equal ease. At the southern polar defence fortress, the vital Eagle Bastion had fallen to the Tyranids and the honour of retaking it was accepted by the surviving detachments of the 1st Company based in this region. The Eagle Bastion provided a solid base to anchor the defences of the fortress and without it there would be almost no chance of continued resistance above ground. Situated on a rocky bluff overlooking the entrance to the underground silos, the bastion had been considered impregnable, but a Tyranid organism was able to infiltrate through the oxy-recyc ducts and slaughtered the valiant defenders of Planetary Defence Auxillia tasked with its defence. The vile creature was eventually destroyed, but not before an uncannily well-coordinated attack carried the walls of the bastion and saw every one of the defenders killed.

Brother Captain Dardinus led his brothers in prayer in the hours before dawn and began the assault on the Eagle Bastion at first light. Unbeknownst to Captain Dardinus, the deviant aliens had laid a trap for him and, as the men of 1st Company stormed the bastion, they found themselves surrounded, every avenue of escape blocked by terrifying creatures bigger than a Dreadnought. Though they knew they were doomed, not a man amongst them was cowed and each vowed to sell his life as dearly as possible. Fighting back to back, the men of 1st Company battled for six hours until at last only Captain Dardinus remained. A beast from the darkest of nightmares faced the brave captain. Fully six metres tall, with four arms and a giant maw filled with serrated fangs, the Hive Tyrant seemed to regard Dardinus with interest as though deciding upon his worth as a foe.

Suddenly the creature's scything talons lashed out and there was a burst of electrical discharge as the captain's power sword parried the blow. The alien screeched and hissed, circling Captain Dardinus more warily now. The beast's claws again struck at the brave captain, but he ducked, rolling beneath its attack and slashed his sword across the Tyrant's flank. Acidic purple ichor sprayed from the wound and the vile creature shrieked in pain. Captain Dardinus scrambled to his feet and parried another strike of the Tyrant's claws. He bled from a score of cuts, but fought with the strength of the Primarch. The Tyrant attacked again and its barbed tail whipped forwards, punching through the captain's breastplate. As Dardinus reeled, the creature's chest spasmed and fleshy lengths of tough muscle fibre fired out to ensnare the captain. Serrated hooks tore into Dardinus' armour and dragged him into the Tyrant's embrace. The beast's talons plunged deep into the captain's body and tore through his flesh, ripping him in two at the midriff. Thus it was that the Eagle Bastion was lost.

At the top of the world, in the northern polar region, the 1st Company detachments were under the command of Brother Captain Adrasta. Despite the bravest resistance, the men of the company were forced underground. Unstoppable waves of the aliens poured over the defence silo, overrunning the surface outposts and bunkers and all subsequent contact with the men of the 1st Company was lost. By this time, the Tyranids were forced to pay a heavy price for every foot they advanced. Running battles were fought amongst the gigantic coolant stores and capacitors of the defence laser batteries. The darkness was lit by the flash of lasers, bolters and the white heat of flamers. Screams, weapons fire and alien howls were the only sounds and many heroes were made in these dark and desperate times. Ultimately, there could be only one outcome to the battle and as the surviving members of 1st Company were pushed back into the Penitorium, every man knew that this was the moment of his death. Chanting the Catechism of the Warrior, the Space Marines fought like heroes of legend and sold their lives dearly. When the brethren of 3rd Company retook the defence silo they discovered a mound of Tyranids, six deep, surrounding the Terminators who died to a man in the subterranean darkness of their home world. The men of 1st Company had broken the Tyranid attack, but at the cost of their own lives.

As the last warrior of 1st Company fell it is said that the flame that burns in the Chapel of Heroes in the Fortress of Hera guttered and died. And for a hundred nights, it could not be relit, a day of darkness and lament for each warrior of 1st Company".

While battle raged on Macragge, the war in space was still being fought. Marneus Calgar commanded the Ultramarines fleet and filed this report following the Battle of Circe.

My order to pursue the retreating Tyranid force was not given lightly. Though the fleet under my command was vastly outnumbered, I knew that were I to permit the alien menace to escape, we would only have to face it again. The fleet harried the Tyranids to the edge of Ultramar, giving them no succour or respite from our weapons. With no sign yet of the Segmentum Tempestus battlefleet, I knew that constant pressure was the only way we could prevent the Tyranids from regrouping and destroying us.

As we reached the outermost planet of Ultramar, my Astropaths warned me of a great turbulence in the warp. It was approaching at speed, but whether it was the Tempestus battlefleet or the second Tyranid fleet, they could not say. I swear the next few minutes that passed were the longest in my life. Then a storm of torpedoes and a veritable fusillade of laser fire heralded the arrival of the Tempestus battlefleet. Nearly two hundred vessels, led by the Emperor class battleship, the Dominus Astra, emerged from the warp, the anvil to the Ultramar fleet's hammer. Caught between the two fleets, the fate of the Tyranids was sealed, but the alien neither knows or understands the concept of defeat and continued to fight on. In the first moments of battle the Pax Imperator and Clavis Regni were overwhelmed by swarms of monstrous creatures that completely obscured the massive Imperial cruisers with their numbers.

Our experiences in fighting the Tyranids had taught us that the aliens needed the largest hive ships to function effectively and I ordered all ships to concentrate their firepower on a tentacled leviathan that lurked in the centre of the swarm. Our ships punched a hole in the Tyranid centre, scattering them in all directions. Screens of smaller ships blocked the way and though our losses were grievous our vessels were finally able to fight their way through to the hive ships and strike at the vile craft with every weapon that could be brought to bear. Caught in the crossfire of two fleets the Tyranids were finally overcome and after a brutal hour of constant bombardment, the remains of the hive fleet was destroyed and the battle won.

In triumphal procession, the two fleets began the journey back in-system. As we passed the gas giant Circe, the fabric of space was torn aside as the second Tyranid fleet emerged from the warp behind us. Realising that the Tempestus battlefleet could not outrun the Tyranids, Lord Admiral Rath decided to make his stand within the upper atmosphere of Circe. With the fate of the defenders on Macragge uppermost in my mind, I ordered the Ultramar fleet not to engage and to return to Macragge. The Tempestus fleet would stand or fall regardless of whether my few cruisers remained.

The previous Tyranid fleet had been weakened and trapped. This one was fresh and undamaged and as the Tempestus fleet turned at bay, the destruction wrought by the Tyranids was fearful. The Imperial craft could not breach the solid wall of creatures that protected the hive ships, the great bell tolled along the length of the Dominus Astra and it seemed as though all was lost'as the hive fleet closed for the kill. The enormous firepower of the Emperor class warship punched great holes in the Tyranid fleet but for every hit that was scored, another Imperial vessel was overwhelmed and destroyed by the hive ship's protectors and, watching on the hologlobe, 1 believed that our desperate gamble had failed.

The Tempestus fleet simply could not bring sufficient weight of fire to destroy enough of the hive ships to disrupt the Tyranids. Suddenly the Dominus Astra's engines flared as it powered deep into the heart of the Tyranids and a fleet-wide communique sounded within the Sacristy of every Imperial vessel:

"Attention all vessels, this is Lord Admiral Rath. It is clear to me that we cannot win this fight by utilising conventional methods of warfare. I order you all to disengage and withdraw. The Dominus Astra shall be the fiery sword of retribution that ends this war. I repeat, disengage and pull away. The Emperor's blessing be upon you always!"

Realising the Admiral's plan, the remaining captains pulled their vessels away from the battle. The Dominus Astra collided with the largest of the Tyranid craft and as the hive ship's tentacles ensnared the vessel, the Admiral triggered his ship's warp engines. Space was torn asunder as an uncontrolled warp vortex erupted and engulfed the hive fleet in its destructive embrace.

The Tyranids were sucked into oblivion by the vortex and when the coruscating warp field died down, not a single hive ship remained. The Dominus Astra was gone also. The great Bell of Souls on Terra shall chime a thousand times in recognition of the Admiral's sacrifice and his name shall be entered in the Chapel of Heroes as a Defender of Ultramar.

The Battle of Circe had been won, but it had claimed nearly the entire Tempestus battlefleet. A small force of cruisers remained to destroy any surviving bio-ships, while the rest of the fleet limped back to Macragge. Contact had been lost with the defenders in the northern polar regions and thus I ordered the 3rd and 7th Companies ahead to bolster the beleaguered defenders. Only time would tell whether or not they would arrive soon enough.

With the return of the Ultramarines, the remaining Tyranids were soon eradicated. Inquisitor Kryptman returned with them to begin the task of cataloguing the various Tyranid organisms.

Upon arrival on Macragge following the defeat of the hive fleet in space, my first impression was of a hitherto unseen scale of slaughter. So numerous were the Tyranid corpses that a man could walk from one end of the ice fields to the other without once setting foot on the planet's surface. By the time I arrived from Talasa Prime, Ordo Xenos battlefield cleansing units had the situation under control and were following my strict quarantine and species classification protocols. The defences of the polar regions were heavily damaged and bore all the hallmarks of a truly titanic struggle. Gazing upon the disgusting countenance of these aliens for the first time, I realised that not only must we resist them when they invade our space, we must seek them out and destroy them also.

Venturing within the hallways beneath the polar fortresses, I was repulsed to find the internal architecture altered in ways too numerous to count. Obscenely organic constructions filled the corridors and despite their destruction it was impossible not to feel that some presence of the aliens remained. Everywhere I looked, there were signs of fighting. Not an inch of ground had been yielded without fierce resistance. Fire blackened walls and the stench of cooked flesh permeated every surface and I doubt I shall ever truly be rid of that foul odour.

I began cataloguing the many and varied Tyranid creatures in an attempt to gain some kind of understanding into this abominable new race of aliens. The Techno Magi of Mars arrived with commendable speed and began the long task of collecting specimens from amongst the dead creatures. It will take many years of careful study before the true nature of the Tyranids becomes clear, but several things are immediately apparent.

Firstly, the presence of Genestealers in the alien horde seems to point to them being creatures of Tyranid origin. Early genetic scans appear to indicate this, but it will require a more detailed investigation to verify it. These creatures have long been thought of as indigenous to the moons of Ymgarl, and how they came to be there when they are possibly of Tyranid origin remains a mystery. In light of this new information, I recommend a xenocidal campaign against this species be mounted immediately by the Adeptus Astartes and that all Inquisitors increase their vigilance in regards to Genestealer infestations.

Secondly, having seen the destruction wrought by the Tyranids against the realm of Ultramar, I cannot stress enough the danger posed by these creatures. They are the ultimate race of predators, consuming with no thought for anything except the absorption of the next race. Knowing what I know now, I cannot help but feel that this may not even have been a true invasion. As incredible as it seems, this may have been a learning experience for the Tyranids. I have perused several post-action reports all claiming that the Tyranids would rapidly adapt to whatever the defenders could throw at them. If this is the case and the assault on Ultramar was but a probing thrust, then we must maintain a constant vigil on the galactic rim and strengthen our military presence tenfold if we are to resist a more determined Tyranid invasion.

Thus I submit my report and again urge you to act with all possible haste in this matter. I believe that should we underestimate this foe it will be the beginning of the end for humanity. The Tyranids cannot be bargained with, reasoned with or forced to surrender. They absolutely will not stop and the only way we can defeat them is to be ready, to use the time the Ultramarines have bought with their lives to better prepare ourselves for the next Tyranid invasion. It may not be soon, but it will come. And we must be ready for it.