Feeder tentacles vainly attempted to swat away the attacking craft, but their swipes were drunken and uncoordinated. The smaller organisms protecting the hive ship threw off their lethargy, returning to their basic, instinctual desires, but by then it was too late. The Imperial ships were in textbook positions to deliver the deathblow to nearly every one of the drone ships. As though on range practice at Bakka, the Sword of Retribution bracketed one tyranid ship after another, annihilating them with powerful broadsides.

The battered Mortis Probati limped towards the listing hive ship and, in respect to her crew's reckless heroism, every other ship in the fleet hung back, allowing Captain Gaiseric to take the killing shot.

Fluid and fleshy entrails drifted from the mortally wounded beast, its alien lifeblood pumping into space from ruptured arteries and ruined organs. Those tentacles that had not been blasted off twitched spasmodically, and through a great rent. In its upper carapace a vast, pulsing organ could be seen, labouring to keep the beast alive.

A single shell from the strike cruiser's bombardment cannon punched through the tough, fleshy outer layer of the hive ship's heart and detonated within its massive ventricle chambers. The explosion blasted the organ to shredded tissue and with a final, juddering spasm, the hive ship died.

Admiral de Corte breathed a sigh of relief and his bridge crew cheered as they watched the death of the hive ship, its massive heart utterly destroyed by the Mortifactors. De Corte knew he should be furious with Captain Gaiseric for breaking the battle line, but could not deny the fact that his actions had been key to the tyranids' defeat. They went against everything taught at the naval academies, but de Corte knew that the truly great captains were the ones who could sometimes break all the teachings and still emerge victorious.

He didn't yet know if Captain Gaiseric fell into that category, or whether he had just been hugely lucky. Publicly, he would espouse the former, but privately, he suspected the latter. Had it not been for the valiant, but ultimately wasteful sacrifice of Captain Payne's ship, then the corpses of the Mortifactors would even now be joining the listing body of the hive ship. Watching the massive vessel haemorrhaging into the darkness, he mouthed a short prayer to the battle spirits that invested his ship, thanking them for their faithful service in this fight.

'Make a note, Mister Viert,' said de Corte. 'Commission a new victory seal to be added to our glorious ship's honour banner.'

'Aye sir, and perhaps a service of thanks?'

'Yes, a service of thanks to be held in the ship's chapels at vespers for all crew. Thank you, Mister Viert.'

The admiral linked his hands behind his back and returned to his command lectern as Inquisitor Kryptman shuffled along the nave to join him.

'A great victory,' said the admiral, loud enough to be heard by his entire bridge crew.

Kryptman nodded. 'A victory, yes. It remains to be seen whether it is a great one.'

The admiral leaned in close to Kryptman and whispered, 'You and I both know that this engagement has cost us dearly, but it will avail us nothing if we allow our crews to know how costly. I would appreciate your support in this matter.'

Kryptman looked ready to snap back at de Corte, but nodded curtly. 'You are correct, Admiral de Corte. Morale is crucial at this point.'

De Corte accepted Kryptman's acquiescence gracefully and began issuing the orders that would see his fleet disengage from Barbarus Prime and fall back to the orbital docks of Chordelis.

For the viewing bay was filled with a multitude of tyranid creatures rising from their feeding: a collection of hive ships and drones that dwarfed the group they had just destroyed. The Battle of Barbarus had been won, but in the face of such a vast fleet, it would be folly to fight again without first regrouping and rearming.

This had been a great victory, but it was just the tip of the iceberg. The real battles were yet to come.

SIX

Learchus gazed up at the sloping wall that stretched to either side of him for nearly five kilometres towards the valley's flanks. Despite his disappointment in the manner in which this world upheld the ideals of Ultramar, he was pleased at the strength of its construction. Worthy of Macragge itself, he thought. Ten metres high and sheathed in smooth stone, the wall glittered like white marble in the low sun. A small revetment protected its golden gate and an icy moat drained below the level of the road into a sluggish river that wound its way to the plain below.

A foaming waterfall, pouring from the centre of the wall, roared down a copper channel embedded in its centre, fed the moat and filled the surrounding air with a chill mist of icy water. The morning was bitingly cold and his breath feathered before him, though his power armour isolated him from the worst of the frosty air.

Beside him stood a shivering officer of the Tarsis Ultra Citizens' Defence Legion, his blue, fur-collared coat and white peaked cap immaculately clean. In addition to his dress uniform, he wore a grey scarf around his lower jaw and thick mittens, thrust deep in his coat's baggy pockets. His name was Major Aries Satria and he commanded the armed forces of this city in the name of the Fabricator Marshal. His iron breastplate was polished to a silver sheen and the dress sword buckled to his gleaming leather belt shone like gold.

'When winter comes, does this moat freeze?' asked Learchus.

'This far out, yes,' nodded Major Satria, 'but as you get further into the city, the heat gets trapped by the valley sides and keeps them from turning to ice.'

'How far in do they freeze?' pressed Learchus.

'The moats at the first and second walls always freeze, and sometimes the third, but it really depends of the severity of the winter.'

Learchus nodded, setting off for the gate in the wall. 'What is the forecast for this coming winter?'

'The meteorologists say it will be a tough one,' said Satria, hurrying to keep up with Learchus, 'but then they always say that, don't they?'

The winters on Macragge had taught Learchus how tough a winter could be on soldiers, and he knew that the war could not have come at a worse time for this world. The cold weather had caused them problems already, with men reporting frostbite and other cold-related injuries. Corps-men from the Logres regiment were instructing the men of the Krieg and local defence forces how to cope with such severe conditions, but it would take time for such practices to be adopted.

The two men crossed the moat on a crowded steel bridge. Its arching spars were limned with hoar frost and drifting floes of ice were already forming in the water below. Learchus had ordered the bridge to be rigged with explosives so that it could be destroyed upon the first attacks, though he could see that it would not be long before the moat was a solid sheet of thick ice, as easily traversable as this bridge. Nevertheless, standard practice was to destroy all approaches that the enemy could make use of and thus he had ordered it prepared for destruction.

But while the bridge still stood, many of the citizens of Erebus were making good use of it. Its metal deck vibrated with the passage of scores of vehicles, which rumbled past Learchus and Satria in the direction of the main spaceport below. All manner of vehicles, from gleaming limousines to battered agri-transports, streamed through the wall's main gate, each crammed with people carrying as many of their possessions as they could fit inside.

They stepped from the bridge onto a rutted road caked in grit that led to one of the wall's few postern gates. Tightly packed trucks filled with frightened people passed them and the sudden roar of a nearby starship engine made conversation impossible for a few seconds. Both Learchus and Satria turned, watching a cargo vessel rise from the port facilities and climb into the pale sky on smoky trails. It was the eighth vessel to leave Tarsis Ultra this morning and, judging by the crowds pressing around the walls of the spaceport, would only be one of many.