'Damn thing!' snapped Tiberius. 'What is the meaning of this?'

The skull squealed and darted back, rising into the air and hovering just out of reach. Its twin followed it, pulled up by the copper cable that connected them.

'Do not be alarmed, lord admiral,' said the figure in the doorway. 'The devices are merely mapping and recording a three-dimensional image of your skull.'

Seeing Tiberius's confusion, the robed Space Marine said, 'So that upon your death, it may be placed in the position that most suits its dimensions.'

Tiberius stared open-mouthed at the figure, who pulled back his hood and stepped forward into the light.

His skin was the colour of ebony, his dark hair pulled back in long braids and woven with coloured crystals. Four golden studs glittered on his brow, his full features and dark eyes sombre as he addressed the startled Ultramarines.

'I am Brother-Chaplain Astador of the Mortifactors, and I bid thee welcome, brothers.'

This was not what Uriel had expected of the Mortifactors. After announcing himself, Astador had turned and marched from the chamber of corpses without another word, leaving the astonished Ultramarines to follow. The two servo-skulls floated alongside their master, bobbing just above his head and Uriel wondered what other technological artefacts the Mortifactors utilised. The Ultramarines shunned the use of servo-skulls, preferring that the mortal remains of fallen Imperial servants be interred whole that they might sit at the right hand of the Emperor complete.

The halls of the Mortifactors were gloomy and silent as a tomb. Every portal and chamber they passed through bore more skulls and only now, as he looked closer, did Uriel realise that none were carved or fashioned by human hand. All were real, bleached and dusty with age. Though they saw no inhabitants of the fortress monastery in their long journey, the silence was broken by occasional snatches of hymnal dirges and sombre chants of remembrance.

Uriel's sense of bewilderment rose the further they penetrated this dismal sepulchre. How could warriors of the same blood as his dwell in such a morbid place? How could these sons of Guilliman have deviated so far from the teachings of the primarch? He increased his pace until he was level with Astador.

'Brother Astador,' began Uriel. 'I do not wish to cause offence, but has your Chapter suffered a great loss in its recent history?'

Astador shook his head in puzzlement. 'No. We have returned from the world of Armageddon with much honour and the bones of our fallen. Why do you ask?'

Uriel searched for the right expression. They needed the help of the Mortifactors and the wrong words could dash any hopes of aid. 'The halls of your monastery suggest your Chapter is in mourning.'

'It is not like this on Macragge?'

'No, the Fortress of Hera is a place of celebration, of joy in the service of the Emperor. It echoes with tales of courage and honour.'

Astador was silent for a moment before replying. 'You are a native of Macragge?'

'No, I was born on Calth, though I trained at the Agiselus Barracks on Macragge since I was six years old.'

'And would you say that you were shaped by your home-world?'

Uriel considered Astador's question. 'Yes, I would. I worked on an underground farm from the day I was able to walk. They breed them tough on Calth, and you either buckled down and worked hard or you felt the birch across your back.'

'Did you enjoy your life there?' asked Astador.

'I suppose so, though I barely remember it now. It was hard work, but I came from a family who loved me and cared for me. I remember being happy there.'

'And yet you gave it all up to become an Ultramarine.'

'Yes, in Ultramar everyone trains to be a soldier. I discovered I had a natural talent for war, and I swore that I would be the best warrior Macragge had ever seen.'

Astador nodded. 'You are who you are because of where you come from, Captain Ventris, so do not presume to judge me by your own standards. The world below us was my home, and until I was chosen to become one of the Emperor's warriors, I knew neither sunlight nor joy. These things do not exist on Posul, only a brutal life of darkness and bloodshed. I took three hundred skulls in battle before I was chosen to become a Space Marine and since that day I have killed the enemies of the Emperor. I have since seen the sun, yet still I know no joy.'

'A Space Marine needs not joy, nor glory,' said Learchus. 'Service to the Emperor shall be his wine and sustenance, and his soul shall be content.'

Astador stopped and turned to face the veteran sergeant.

'You quote from the Codex Astartes, sergeant. We have grown beyond the need for such dogma and forge our own path from the wisdom of our Chaplains. To be bound by words set down an age ago is not our way.'

The Ultramarines halted in their tracks, horrified by Astador's casual blasphemy. To have the holy writings of Roboute Guilliman dismissed so lightly was something they never expected to hear from the mouth of a fellow Space Marine.

Tiberius was the first to recover his wits and said, 'Forgive us, Brother Chaplain. But it is surprising for us to hear one whose lineage can be traced back to the blessed primarch speaking in such a manner of the Codex Astartes.'

Astador bowed in respect to Tiberius.

'I apologise if my words caused offence, lord admiral. We venerate the primarch, just as you do. He is our Chapter's father and all our oaths of allegiance are sworn to him and the Emperor.'

'Yet you scorn his greatest work?' snapped Learchus, clenching his fists.

'No, my brother, far from it,' said Astador, moving to stand before Learchus. 'We look upon its words as the foundation of our way of life, but to follow its teachings without consideration for what we have learned and that we see around us is not wisdom, it is merely repetition. Repetition leads to stagnation. And stagnation dooms us.'

Uriel placed a hand on Astador's shoulder and said, 'Brother Astador, perhaps we should continue? We have come to speak with your Chapter Master and do not have time for theological debate. The world of Tarsis Ultra is under threat from the most deadly enemy and we would petition your master for his aid in the coming conflict.'

Astador nodded without turning, then spun on his heel and marched off into the darkness once more. Uriel released the breath he had been holding and unclenched his jaw.

'Damn it, Learchus,' he whispered. 'We are here for their help, not to antagonise them.'

'But you heard what he said about the codex!' protested Learchus.

'Uriel is correct, Learchus,' said Tiberius. 'We are all warriors of the Emperor and that is the most important factor. You know there are other Chapters that do not follow the words of the primarch as closely as we do. The sons of Russ follow their own path, and we count them as allies do we not?'

Learchus nodded, though Uriel could see he was not convinced.

Uriel's gaze followed Astador as he continued onwards through the darkness of his fortress monastery. The skulls of fallen Mortifactors stared back at him from the walls. Uriel sighed. Certainly time and distance could change a Chapter a great deal, no matter how similar their ancestry was.

Astador turned and beckoned them onwards.

'Come, Lord Magyar awaits.'

The Gallery of Bone was aptly named, thought Uriel as he stood awaiting the audience with Lord Magyar, Chapter Master of the Mortifactors. A carven cloister of bone surrounded a stone flagged floor paved with hundreds of tombstones. Niches set within the columns of the cloister contained skeletal warriors clutching swords and the entire, domed ceiling was formed from interlocked skulls, their eyeless sockets glaring down at those who stood within their domain. The four Ultramarines stood in the centre of the wide space enclosed by the cloister, Uriel and Tiberius to the fore, Learchus and Pasanius standing at parade rest behind them.