Mortuary statues of angels flanked a vast throne composed of the bones of long-dead Space Marines. Uriel could pick out individual femurs, spines and many other bones as well as grinning skulls leering from the armrests and above the tapered top of the throne.

A bone-legged table stood beside the throne with a flattened bowl of dark enamel atop it. Everywhere Uriel looked, death was venerated and exalted above all things.

Astador stood close to the throne, the hood of his black robe cowling his face once more.

A deep gong sounded, and hidden doors behind the throne swung silently open. The first of a long procession entered the Gallery of Bone. Dozens of hooded figures shuffled into the chamber, some swinging smoking censers, others chanting a sombre lament, but all with their heads cast down. One by one they took up positions around the chamber until each skeleton-filled niche had a living twin standing before it. Two Terminators in dark armour decorated with bone trim marched into the chamber, each carrying a long, wide-bladed scythe. Their helmets were carved to resemble screaming skulls and Uriel could well imagine the terror that these warriors must evoke in their enemies. The Terminators took up position either side of the throne as a winged skeleton, no larger than a child, flapped into the gallery on fragile-looking wings with thin, membranous remnants of tattered vestments fluttering between each of its wing bones. It settled upon the top of the throne and squatted there, silently regarding the shocked Ultramarines. Brass wire glittered at its joints and Uriel could see a tiny suspensor generator attached to the spine between its wings.

Uriel's lip curled in distaste at the sight of the winged familiar as a tall figure, clad in armour of bone entered the gallery. His movements were slow and unhurried, every step considered and solemn. His breastplate was formed from long ribs, bent and fashioned into shape, the Imperial eagle at its centre as skeletal as the winged familiar that watched the proceedings below. Every piece of this warrior's armour, from the greaves to the vambrace, cuissart and gorget was formed from bone. He carried a gigantic scythe, its blade silvered and sharp, the haft gleaming ebony.

Lord Magyar, for it could surely be none other, stood before his throne and bowed to the Ultramarines. His long, silver hair was tied in numerous crystal-wrapped braids reaching to the small of his back and his coal-dark skin resembled a lunar landscape, cratered and ridged with numberless wrinkles. A long, forked white beard fell to his waist, waxed into sharp points.

His eyes were dark pinholes and though it was impossible to guess the age of the Chapter Master, Uriel was certain he must have been at least seven hundred years old.

Lord Magyar sat upon his throne and said, 'You are welcome, brothers of the blood.'

Uriel was shocked at the strength and powerful authority in the ancient warrior's voice, but hid his surprise as he stepped forward and bowed.

'Lord Magyar, we thank you for your welcome and bring greetings from your brothers of Ultramar. Lord Calgar himself bade me convey his regards to you.'

Lord Magyar nodded slowly, accepting Uriel's greeting.

'You come with dark tidings, Captain Ventris. Our Chaplains have seen grave portents and they have seen you.'

'Seen me?' asked Uriel.

'Seen you drenched in blood. Seen you triumphant. Seen you dead,' proclaimed Magyar.

'I do not understand, my lord.'

'Long have we known of your coming to us, Uriel Ventris,' nodded Magyar, 'but not why. Tell me why you have come to my monastery, brother of the blood?'

Pleased to be on a topic he could understand, Uriel bowed again to Lord Magyar.

'We come before you in hopes that you will honour the Warrior's Debt and join us in battle against a terrible enemy.'

'You speak of the oath Guilliman swore on Tarsis Ultra during the Great Crusade.'

'I do, Lord Magyar.'

'Such an oath binds your Chapter still?' asked Magyar.

'Yes, my lord. As has been our way since the blessed primarch swore his oath of brotherhood with the soldier who saved his life, we are sworn to defend the people of Tarsis Ultra should their world ever be threatened,' said Uriel.

'Is it so threatened?' asked Magyar formally.

'It is, my lord.'

'You are sure?'

'Yes, my lord. A tendril of the Great Devourer is moving towards it and will attack soon. My warriors and I recently boarded and destroyed a hulk codified as the Death of Virtue that was bound for Tarsis Ultra. The accursed vessel was filled with genestealers and we fought them with courage. Upon returning to our ship, our astropaths detected the psychic disturbance known as the Shadow in the Warp moving towards us. The tyranids are coming, my lord. Of this I am sure.'

'And what do you wish of me?'

'My Chapter is honour bound to defend these realms and I call upon the blood that flows between us for your aid. The tyranids are a monstrous foe and we will be sorely pressed to defeat them. With your valiant warriors by our side, we would stand a much greater chance of victory.'

Lord Magyar grinned, exposing brilliant white teeth. 'Do not think to appeal to my warrior's vanity, Captain Ventris. I know of this debt and the bond that exists between us full well.'

'Then your warriors will fight beside us?'

'That remains to be seen,' said Magyar, beckoning to Astador.

Astador stood beside his lord and master, awaiting his command.

'You will perform a vision-quest, Brother Chaplain Astador?'

'Yes, my lord. As you command,' said Astador opening his robe and allowing it to fall to the tombstone floor. His armour was the colour of spilt blood, dark and threatening, the trims formed in gold. Obsidian skulls adorned each shoulder guard. He carried a golden-winged crozius arcanum, his weapon and a Chaplain's symbol of authority.

He leaned down and removed one of Lord Magyar's gauntlets, placing it next to the bowl on the table. Next, he raised the razor edge of his crozius and slashed it across his master's palm, allowing the blood to spatter into the bowl. Lord Magyar clenched and unclenched his fist repeatedly to prevent the blood from clotting until the bowl was full.

Astador lifted the bowl and offered it to Lord Magyar who accepted it with a respectful nod. The Chapter Master supped his blood and handed the bowl back to Astador.

The Chaplain, lifted it to his lips and poured the blood over his face in a red rain. He drank deeply of his master's blood and Uriel grimaced in distaste. What manner of barbaric ritual was this that required the blood of fellow Space Marines to enact? Had the Mortifactors become so debased that they had fallen into rituals more commonly associated with the Ruinous Powers? He glanced over at Tiberius.

The lord admiral's face was unreadable, but Uriel could see the muscles bunched at his jaw and took his cue from him. Astador groaned and reached out a hand to steady himself. The bony familiar perched atop Magyar's throne took to the air and flapped noisily towards the swaying Chaplain, catching the bowl as it fell from his slack fingers.

Uriel could contain himself no longer and shouted, 'What is he doing? This reeks of impure sorceries!'

'Be silent!' roared Magyar. 'He seeks guidance from our revered ancestors. Their wisdom comes from beyond the veil of death, unfettered by the concerns of the living. He seeks their counsel on whether we should join you in this fight.'

Uriel was about to answer when he felt an iron grip on his arm. Lord Admiral Tiberius shook his head slowly.

'The Devourer comes from beyond the galaxy, and even by naming it, men betray their ignorance,' groaned Astador. 'The immortal hive mind controls its every thought. So many beings… A billion times a billion monsters form the over-mind and there is none here who can comprehend its scale. It comes this way and seeks only to feed. It cannot be negotiated with, it cannot be reasoned with, it can only be fought. It must be fought.'