Admiral Tiberius would understand that, but Ventris was the protege of Captain Idaeus, a captain he had seen on Macragge following the defeat of hive fleet Behemoth. He would need to be wary of Ventris's puritanical anger.

Fortunately, he had sufficient force to ensure that Ventris would be kept in line.

The blue and white curve of Tarsis Ultra shone at the bottom of the viewing bay, dozens of system ships and defence monitors hanging in orbit around the planet. There was a formidable force arrayed here and the Ultramarines' demonstration of how effective a weapon the refineries could be as floating bombs had not gone unnoticed. The last refinery hung in high orbit, a fleet of servitor-manned tugs ready to drag her into the heart of the tyranid fleet and unleash fiery destruction.

The inquisitor limped to his desk and sat behind its sweeping nalwood expanse. It had been commissioned hundreds of years ago for his mentor from a world whose name he could not now remember, and was a work of impressive craftsmanship. It never failed to intimidate those who came before him - not that he expected a Space Marine to be intimidated by a mere desk - but it gave him a sense of place whenever he sat behind it.

He knew that the Ultramarines would even now be on their way to his chambers.

Kryptman touched the vox-bead at his collar and said, 'Captain Bannon, could you and Chaplain Astador come in here.'

Uriel marched past frightened-looking naval ratings and techs as he, Tiberius and Pasanius made their way towards the basilica of the star fort. The orbital space station was a massive construction, impossibly ancient and, together with the others in the linked chain, powerful enough to defeat a battleship together with any attendant escorts, and even through his anger, Uriel could see that they would be potent weapons in the fight against the tyranids.

As they had drawn closer to the star fort, he had seen the vast shape of the last refinery anchored thousands of kilometres away from the nearest vessel, remotely piloted ships packing its structure with even more explosives. Proof positive that Kryptman had never intended to save Chordelis.

The trio passed through the northern quadrant of the star fort, entering the central basilica where Inquisitor Kryptman awaited. A black uniformed armsman directed them to the chambers the inquisitor had requisitioned and as they approached the door, Admiral Tiberius took hold of Uriel's arm and said, 'Remember, Uriel. Kryptman is not a man to cross, so be mindful of what you say.'

'I will,' promised Uriel and rapped his gauntlet on the door, pushing inside without waiting for an answer. Tiberius nodded briskly to Pasanius, who swiftly followed his captain inside.

Uriel pulled up short as he saw Kryptman seated behind an ugly desk of a dark wood, two Space Marines flanking him. He recognised Astador and took the other for one of the Mortifactors until he saw the silver inquisitorial symbol on his left shoulder guard. The yellow of the Imperial Fists Chapter on his other shoulder was a stark contrast to the midnight black of his armour, his skin deeply tanned and his hair a close-cropped blond.

'Ah, Captain Ventris,' said Kryptman. 'Allow me to introduce Captain Bannon of the Deathwatch.'

'Deathwatch…' breathed Uriel. The Chamber Militant of the Ordo Xenos, the elite alien fighters in which he himself had once served for a decade. Kryptman had said that he had requested a Deathwatch kill team, but Uriel had not expected them to arrive in time for the coming conflict.

Formidable killers of xeno creatures, each member of the Deathwatch was chosen from the finest warriors of his Chapter to serve for a time with the Ordo Xenos to combat the Mistreat of aliens throughout the galaxy. There were none better qualified to join this fight than the Deathwatch, and seeing the stylised skull symbol on Bannon's shoulder guard immediately filled Uriel with fresh hope.

He marched towards the gaudy desk and leaned forwards, resting his fists on its surface. He locked eyes with the inquisitor and said, 'You lied to us.'

'You allowed yourself be lied to, Uriel,' said Kryptman. 'Did you really think I was a man who changes his mind on a whim?'

'No, but I thought you were a man of your word. Everything I have learned of you has led me to believe that you were a man of honour.'

'Then you are naive indeed,' said Kryptman. 'I am a man who gets the job done.'

'Even if that means murdering innocent people?'

'If it proves necessary, then yes.'

'I do not know who I hate more just now. You do not see the tyranids killing one another to achieve victory.'

'Not yet,' answered Kryptman with a sly smile.

'You would do well to watch your tone, Captain Ventris,' said Astador, circling the desk to stand face to face with Uriel. 'Your Chapter owes this man its very existence.'

'Get away from me, Astador,' warned Uriel.

'You will mind your place, Captain Ventris,' said Astador. 'We all have a part to play in this war. You must accept yours as I accept mine.'

Uriel felt his anger towards Astador flare and before he knew what he was doing, he hammered a thunderous right cross against the Chaplain's jaw. Astador spun backwards, crashing into the wall, but before Uriel could capitalise on the surprise of his attack, he felt a powerful grip encircle his neck and a burning heat prickle the skin beneath his jawline.

'If you so much as move, I will plunge this power knife up through your soft palate and into your brain,' said Captain Bannon. Astador surged to his feet, a killing light in his eyes, and in them, Uriel could see the feral tribal warrior he had been on Posul.

But before he could move, Pasanius was there, his massive hand wrapped around the Mortifactor's neck. He held the struggling Chaplain in a grip of steel.

'Don't,' he said.

'All of you, stop this madness now!' bellowed Tiberius, stepping into the centre of the room. He stared at Bannon and said, 'Take that knife away from my captain's throat,' before turning to Pasanius.

'Sergeant, let go of Chaplain Astador and step away from him.'

Pasanius looked round at Uriel, who nodded, the movement almost imperceptible due to the glowing amber blade at his neck, and released the Mortifactor. Astador's eyes blazed fury, but he made no aggressive moves and Pasanius stepped back, radiating threat and the promise of fresh violence should the Chaplain attempt anything further.

Bannon withdrew the knife from Uriel's neck and said, 'I know of you, Captain Ventris, and I have a great respect for what you have done in the past, but we must be united in this common cause. It ill becomes us to fight amongst ourselves when there is a terrible foe who seeks to destroy us all.'

Uriel nodded and unconsciously rubbed his neck where the burning edge of Bannon's power knife had singed his skin.

'Captain Bannon speaks true,' said Tiberius. 'We are all servants of the divine God-Emperor and must comport ourselves accordingly. We are not animals or blasphemers who have cast off the codes of moral behaviour. There is to be no more violence between us.'

The tension in the room slowly ebbed away and Bannon offered his hand to Uriel.

Uriel took a deep, calming breath before taking Bannon's hand, feeling the killing rage drain from his body, leaving him vulnerable and ashamed. Deep inside he felt the touch of an ancient being within him and heard its diabolical laughter echoing within his soul.

'Come,' said Kryptman, when he sensed his audience had calmed. 'We have much to discuss. While we have been fighting the tyranid fleet, Magos Locard has been busy in the biologis research labs on Tarsis Ultra and his findings are most illuminating.

Blinding clouds of hot steam filled the train platform as another land train pulled into its designated berth and Pren Fallows, the platform overseer, cursed as his snow goggles fogged with condensation. He pulled off the goggles and wiped the inner face clear with the sleeve of his overalls. There was precious little snow here anyway, the heat generated by the land trains and the hundreds of milling people soon turned the snow and ice to a shin deep mucky slush.