'But can they be defeated?' asked Stagler simply.

Kryptman laughed humourlessly. 'Oh yes, Colonel Stagler, they can be defeated, but only at terrible cost.'

'The cost is irrelevant,' said Stagler brusquely. 'All that matters is that we can defeat them, yes?'

Inquisitor Kryptman arched an eyebrow before inclining his head towards Uriel saying, 'Colonel Stagler has a point. Perhaps Captain Ventris would favour us by recounting the tale of Hive Fleet Behemoth and the Battle of Macragge?'

'It would be my pleasure, lord inquisitor,' said Uriel proudly, standing and clasping his hands behind his back.

'Hive fleet Behemoth came from beyond the halo stars of the eastern fringe, its numbers too vast to count. Their alien ships descended upon Macragge, but the noble Lord Calgar, forewarned by Lord Kryptman here, had assembled a powerful fleet to defend the holy soil of our homeworld. Fearsome battle raged in space until Lord Calgar pulled back, drawing the hive fleet onto the guns of Macragge. Whilst the aliens were spread out and vulnerable, he turned and struck, his vessels crippling one of their accursed hive ships and fatally disrupting their fleet.'

'I don't understand, Captain Ventris,' said Colonel Rabelaq. 'How could the loss of one ship cause so much damage to their fleet?'

'I will answer that,' put in Magos Locard. 'To understand the motivational imperatives of the tyranids, one must first understand the nature of their consciousness. A hive fleet is made up of billions upon billions of living organisms produced in the hive's reproductive chambers by the Norn Queen. Essentially, each ship is a living creature, every organism that makes up that ship existing only to serve the ship, and each ship functioning only as part of the fleet. A gestalt consciousness links every creature in the fleet, from the mightiest warrior beast to the tiniest, microscopic bacteria of the digestion pools, creating a vast psychic consciousness we call the overmind, that is capable of exerting a monstrous will and alien intelligence. Of course these creatures have no individuality of their own and exist simply to serve the hive mind. If one can disrupt the psychic link between them, the lower organisms become confused, often reverting to their basic, animalistic natures. It is the key to defeating them.'

'Yes,' continued Uriel, 'when Lord Calgar's fleet destroyed the largest hive ship, they were able to reap a great tally in bio-ships as the aliens' attacks became increasingly uncoordinated and random. Their fleet was driven from Macragge, and though thousands of spores, each bearing a tyranid organism, had been released above the polar defence fortresses, Lord Calgar gave chase to the fleeing enemy.'

'He left his world undefended?' asked Stagler, disapprovingly.

'No, colonel, far from it,' said Uriel. 'The polar defence fortresses were held by Terminators of the First company as well as brave warriors from the defence auxilia and Titans of the Legio Praetor. Lord Calgar was confident they could hold, and pursued the tyranid fleet to the ringed planet of Circe. Together with recently arrived ships from Battlefleet Tempestus, he destroyed the tyranid fleet in a great battle. We had defeated the tyranids, but at a grievous cost. Hundreds of thousands died, the flagship of the Tempestus fleet, the Dominus Astra, was lost and our entire First company was killed, including my own ancestor, Lucian Ventris. Only now does it regain its full strength.'

Uriel sat back on the bench as Kryptman picked up the tale.

'Hive fleet Behemoth was no more, but the tyranids had learned from their defeat and when they returned at the head of a new hive fleet - which we named Kraken - less than a decade ago, it was on a much greater scale. Entire sectors in the eastern fringes have been swallowed by the psychic interference of the tyranid warp shadow, and yet there is worse to come. I have detected a pattern amongst a seemingly random series of attacks across Segmentum Tempestus, Ultima Segmentum and even Segmentum Solar that leads me to believe yet another hive fleet is attacking, this time from below the galactic plane. I have named it Leviathan and it appears that a splinter fleet from Leviathan threatens this world. We must stop the tyranids, gentlemen. Here and now. For if the Shadow in the Warp is allowed to smother the divine light of the Astronomican, then Humanity will surely perish. Ships will be unable to navigate the warp, communication across the galaxy will cease and the Imperium will collapse. Make no mistake, we are fighting for the future of our very race and I am willing to make any sacrifice to ensure its survival.'

The assembled commanders were silent as they took in the scale of the coming conflict, the stakes and their part to play in it. Even Montante now seemed to appreciate the seriousness of the situation and nervously chewed his bottom lip.

'What measures have been taken to prepare this system for the tyranids' attack?' asked Astador.

'Lord Admiral Tiberius is working with Admiral de Corte to devise a strategy to delay the tyranid fleet before it reaches this world,' answered Uriel, 'but, it is apparent that the defences of this city have fallen into disrepair in many places, and we will need time to ready them for the coming assault.'

'Captain Ventris is correct,' nodded Kryptman. 'I have requested the deployment of warriors from the Deathwatch, the Chamber Militant of my ordo, and we will be able to count them amongst our forces before long. However, we must delay the tyranid advance, but we cannot deploy the fleet until we know exactly where the attack will come.

'Astropaths are reporting ripples and eddies in the warp, consistent with those that presage the arrival of a fleet, but the distortions caused by the Shadow in the Warp are making it impossible to pinpoint. We would end up chasing ghosts.'

'The Krieg regiment will have its men and armoured units on the ground within the next three days,' said Stagler. 'We will begin augmenting the city's defences and I have devised a training regime that will ensure our readiness for when these aliens arrive. These aliens will not soon forget the Death Korp.'

Uriel said, 'I shall assign Sergeant Learchus and a squad of Ultramarines to you to aid your training program. He is the finest instructor sergeant Agiselus has ever produced and I am sure will be of great help to you.'

'Thank you, Captain Ventris,' acknowledged Stagler. 'I welcome your aid.'

Rabelaq spoke next. 'My soldiers will be deployed by the end of the day. We have far less armour to land than Colonel Stagler's regiment and by morning I will have units moving throughout the continent to escort people back to the safety of the city. As the soldiers of the Logres regiment are raised from an ice world, this climate will present no difficulties for them, and we may also be able to teach you all a thing or two about cold weather injuries as well. To be honest, our main duties to this point have been protecting krill farmers from raiding Tarellian dog soldiers. It will do them good to have a taste of proper soldiering.'

Fabricator Montante said, 'My PDF regiments have been drilling ever since we received warning of the tyranids. As head of the PDF, I've ordered increased training over the last two months and called up all the citizen militia units to participate too. The vast majority of them have been on training exercises recently and are looking top notch, if I do say so myself. We've also begun stockpiling medical supplies, ammunition, fuel and food and drink in the caverns below the city.'

Kryptman looked surprised at this new side of the Fabricator Marshal and nodded.

'Excellent. That was to be my next point of concern.'

'Oh, don't worry about that, Inquisitor Kryptman. If there's one thing I know, its organisational logistics. I may not be a soldier, but I can organise your supplies better than anyone and make sure that every soldier has a full pack of ammunition and three hot meals a day.'