Swiftly he cut himself free of the giant tyranid beast's maw and dragged his legs from the glutinous, sucking orifice. He felt a hand on his shoulder and pushed himself to his feet in time to see Bannon and the rest of the Space Marines backing away from the charred carcass of the monster towards the Rhinos.

'Come on,' snapped Bannon, his tone angry. 'It is dead. We must get away.'

'Aye,' gasped Uriel, staggering after the captain of the Deathwatch.

As he climbed inside the scorched and ichor-stained Rhino he felt nothing but shame as he pictured his frenzied, uncontrolled raging attack.

Darkness was several hours old by the time the all clear sounded. With the death of the swarm leader, the tyranid attack had foundered, the alien creatures milling in panicked confusion as the controlling will was stripped from the majority of them. Furious counterattacks from the Space Marines and disciplined firing protocols soon dispatched any remaining creatures that still appeared capable of independent action and as the temperature dropped to twenty below freezing, most of the tyranids froze to death where they stood.

Some survived by burrowing into the depths of the snow, where their increased reserves of fat allowed them to enter a form of short-lived hibernation, but these were few and far between. There were not, however, the resources to hunt them down as the subzero temperatures prohibited all but the most essential movements among the defenders.

Such a manoeuvre was even now being undertaken as the Imperial forces retreated to the second trench line. Realising that the first line would not hold against another attack, Colonels Stagler and Rabelaq had decided to pull back on the heels of what was being promoted as a great victory.

But with aerial reconnaissance promising yet more incoming swarms, at least triple the size of this vanguard, and each counting towering beasts that rivalled the size of Battle Titans among their number, there were no illusions among the high command that this victory was anything other than a stay of execution.

ELEVEN

A blue glow filled the command bridge of the Capitol Imperialis, throwing the faces of the command staff into stark relief. Hooded servitors sat immobile before their consoles, insulated bundles of cables snaking from the backs of their robes to sockets in the grilled floor. A lilting chant of imprecations to the machine god drifted from bronze speakers on the ceiling. Sputtering recyc-units tried to keep the atmosphere cool, but the temperature in the command bridge was still stifling.

Uriel did not like being in this armoured leviathan: it ill-suited the Space Marine way of war to be so static and the Codex Astartes frequently pointed out the need for mobility on the battlefield. But recently he had paid little more than lip service to the teachings of his primarch's holy tome. Learchus had made no secret of his disapproval of Uriel's helter-skelter journey on the roof of a Mortifactors' Rhino, claiming it was a foolish stunt more in keeping with the Sons of Russ than a proud Ultramarine, and Uriel was inclined to agree with him.

He shook his head clear of the memory and returned his attention to matters at hand.

The situation was not good.

A holo-map with a rippling green representation of the landscape surrounding Erebus filled the centre of the columned chamber, grainy static washing through the image every few seconds. Information received from various sources fed into the display, picking out Imperial units and positions of incoming swarms. Colonel Rabelaq stood at the end of the map, flanked by his aides and adjutants, while Uriel and Colonel Stagler stood on one side of the map with Chaplain Astador and Captain Bannon on the other.

'It appears that Hera's Gate and Parmenis have both fallen,' began Rabelaq. 'We've been unable to raise Imperial forces in either one of them, and the squadron of Lightnings we sent to obtain visual reports on Konoris and Inyiriam have failed to return. We must assume that the forces that destroyed them are now inbound on our position.'

'And what of the forces that are already moving towards us?' asked Stagler, still wearing his Krieg greatcoat and colback despite the heat.

Rabelaq didn't answer immediately, his consternation evident. 'Ah, well, that we're not sure of. It appears a great many of them have scattered or gone to ground, and we're assuming that they've burrowed into the snow for shelter, as animals are wont to do in winter, to await the arrival of the other swarms. A great many of our reconnaissance assets have already been lost and I felt it would be unwise to lose any more for what would in all likelihood not gain us much more information than we already know.'

Stunned silence greeted his pronouncement, before Bannon leaned over the map and said, 'It is a mistake, Colonel Rabelaq, to assume that these aliens will behave like animals, and if there is one thing I have learned about the tyranids, it is that you do not want to let them out of your sight, even for a second.'

'Yes, well, that's as maybe, Captain Bannon, but if you look at the map, you'll see that we have three distinct swarms of creatures closing on our position. Originally, the southernmost swarm would have reached us first, but it appears as though it has altered the speed of its advance so that all three will arrive together.'

'Clever,' mused Astador, 'very clever. They have learned that we can defeat one swarm, and gather to overrun in one massive charge.'

Uriel watched the icons on the holo-map crawl slowly across the flickering representation of the surface of Tarsis Ultra. Something nagged at the back of his mind, but he could not put his finger on what. He knew it was something simple, but of great import.

'And what is happening in space?' asked Captain Bannon. 'Have we been able to make contact with the fleet?'

Uriel said, 'The Shadow in the Warp is still making astropathic communication impossible, but we have been able to make brief contact with Lord Admiral Tiberius over the long-range vox-caster. Communications are still very fragmentary and we are having trouble maintaining the link through the electromagnetic interference generated by the hive fleet.'

'And what is his situation?' said Astador.

'The admiral has the fleet at anchor around the agri-world of Calydon, though he tells me that a great many vessels are heavily damaged.'

'Have the tyranids not tried to engage him?' asked Bannon.

'Not in any strength, no. It would appear that there are only two hive ships remaining in orbit, so the aliens do not have the capability to effectively control their forces here and despatch an expeditionary force to destroy the fleet.'

Bannon asked, 'Then is the fleet in any shape to offer us support?'

'Potentially,' said Uriel. 'Admiral Tiberius has suggested a plan of attack, but I need to confer with the Fabricator Marshal before expounding further on this. For the moment, no, we are on our own.'

Heads nodded around the map table as each commander digested Uriel's information.

'Then, in short, gentlemen, we have no other choice but to pull back behind the city walls,' said Rabelaq. 'The trenches simply can't hold against these numbers. The walls will prevent the smaller brood organisms from attacking and we have ample guns positioned there to pick off the larger beasts.'

'I agree with Colonel Rabelaq,' said Astador. 'We must accept that the city will suffer under the attack. Better to fight on our terms than theirs.'

Reluctantly, Colonel Stagler nodded, though Uriel could see it irked him to give ground, even when it would be suicide to stand and fight.

'The Krieg regiment will provide the rearguard for the retreat,' he said, almost spitting the words. Uriel looked at the map again and suddenly his nagging worry came to the fore of his mind.