He froze.

But whatever other senses it may have possessed, the creature did not register the touch and ignored him.

Uriel edged past the oblivious monster.

The second beast took to the air as he drew near the end of the path and—

One beat…

The delirium spectre twisted in midair, giving voice to an ear-splitting shriek as it heard the thudding beat of his heart. The flocks above ceased their confused wheeling and turned as one towards them, screeching in triumph.

'Move!' shouted Uriel, abandoning all subterfuge and running for the cave mouth, ducking below the first spike and threading his way between the others to reach the entrance. He staggered inside, gasping a great lungful of air. His chest was a raging inferno as his hearts suddenly leapt from a virtual standstill to their normal rhythm in a matter of moments.

He pushed into the stygian darkness of the cave, dropping to his knees as he fought to stabilise his internal organs and willed himself not to slip into a sleep he knew he would not wake from.

Pasanius backed into the cave, his flamer billowing out a cone of blazing fuel.

The delirium spectres flapped noisily around the entrance to the cave, screaming in anger at being denied their prey. Several darted in to attack, but only succeeded in skewering themselves on the sharp spikes protecting the entrance. Their thrashing bodies ripped apart, their torn skins and iron frames tumbling down the cliff as they died.

Uriel let out a juddering breath, knowing how close they had come to death.

'Pasanius, are you all right?' he gasped.

'Barely,' wheezed Pasanius. 'By the Throne, I never want to have to do that again. It felt like I was dying.'

Uriel nodded, pulling himself upright using the walls of the cave. His returning vision easily penetrated the gloom of the cave and he saw that they were in a long, arched tunnel carved into the rockface, but by who or what he could not tell.

'Well, at least we are safe for the moment,' said Uriel.

'Don't be too sure about that,' replied Pasanius, kicking over a cracked human skull that lay on the floor.

The two Space Marines made their way carefully along the tunnel, the screeching wails of the delirium spectres fading the further they penetrated into the mountain. Their enhanced eyesight magnified the glow from the hissing nozzle of Pasanius's flamer such that they walked through the utter darkness as though their steps were illuminated by glow-globes.

'Who do you think made these tunnels?' asked Pasanius, staring at the marks of picks and drills cut into the rock.

'I have no idea,' said Uriel. 'Perhaps slaves or the populace of this world before it was taken by Chaos?'

'I still can't believe we have travelled so far,' said Pasanius. 'Do you really think this is Medrengard? Can we really be in the Eye of Terror?'

'You saw the dark city beyond the mountains. Can you doubt that one of the fallen primarchs dwells there?'

Pasanius made the sign of the aquila over his chest to ward off the evil that went with even thinking about such things. 'I suppose not. I felt the evil as a poison in my bones, but to come so far… it is impossible, surely.'

'If this is truly the Eye, then nothing is impossible,' said Uriel.

'I had always believed that the stories of worlds taken by daemons and the Ruinous Powers were nothing more man dark legends, exaggerated tales to scare the unwary into obedience.'

'Would that they were,' replied Uriel. 'But as well as destroying these daemonculaba that Librarian Tigurius saw in his vision, I believe that we have been brought to this place to test the strength of our faith as well.'

'And have we failed already?' muttered Pasanius. 'To truck with a daemon…'

'I know, I have put our very souls at risk, my friend,' said Uriel. 'And for that I am sorry. But I could see no choice other than to make the Omphalos Daemonium believe we would do as it wished.'

'Then you don't plan on getting it this Heart of Blood, whatever that is?'

'Of course not,' said Uriel, appalled. 'Once we find it, I intend to smash the vile thing into a million pieces!'

'Thank the Emperor!' breathed Pasanius.

Uriel stopped suddenly. 'You thought I would acquiesce to the desires of a daemon?'

'No, but given how we ended up here and what it threatened…'

'Breaking faith with the Codex Astartes is one thing, but trafficking with daemons is quite another,' snapped Uriel.

'But we have been cast out by the Chapter, banished from the Emperor's sight and are probably trapped forever in the Eye of Terror,' said Pasanius. 'I can see why you might have thought it could have been an option.'

'Really?' demanded Uriel angrily. 'Then tray explain it to me.'

Pasanius did not meet Uriel's gaze as he said, 'Well, it seems likely that the Heart of Blood is some daemonic artefact meant to bring ruin upon an enemy of the Omphalos Daemonium here in the Eye, so might not we be doing the Emperor's work by stealing it from its current master?'

Uriel shook his head. 'No. That way lies madness and the first step on the road to betraying everything we stand for as Space Marines. By such steps are men damned, Pasanius, each tiny heresy excused by some reasonable explanation until their souls are irrevocably blackened and shrivelled. With no Chapter to call our own, some might say that our only loyalty now is to ourselves, but you and I both know that is not true. No matter what becomes of us, we will always be warriors of the Emperor in our hearts. I have told you this before, my friend. Do you still doubt your courage and honour?'

'No, it is not that…' began Pasanius.

'Then what?'

'Nothing,' said Pasanius eventually. 'You are right and I am sorry for even thinking such things.'

Uriel locked his gaze with that of his friend. 'Do you remember the story of the ancient philosopher of Calth who spoke of a stalactite falling in a cave and asked if it would make a sound if no one was there to hear?'

'Aye,' nodded Pasanius. 'It never made sense to me.'

'Nor I, at least until now,' said Uriel. 'Though we have been exiled, we retain our honour and though it is likely that the Chapter will never hear of our deeds, we will continue to fight the enemies of the Emperor until our dying day. Yes?'

'Yes,' agreed Pasanius, slapping his hand on Uriel's shoulder guard. 'And that's why you were captain and I was just a sergeant. You know all the right things to say.'

Uriel chuckled. 'I don't know about that, I mean, look at us, tens of thousands of light years from Macragge and stuck in a cave in the Eye of Terror.'

'…filled with corpses,' finished Pasanius.

Uriel turned and saw that Pasanius was right. The tunnel had widened into a domed cave with rough walls and a number of shadowy passageways leading away. The remains of a long dead fire filled a deep firepit at the centre of the cave, a thin shaft of weak light spearing down from a smoke vent in the roof. Skeletal bodies littered the floor of the cave, splayed and broken, scattered throughout the cave, the bones dusty and cracked.

'Throne! What happened here?' whispered Uriel, circling the firepit and kneeling beside a rag-draped skeleton.

'Looks like they were attacked while they cooked a meal,' said Pasanius, poking around in the remains of the fire with his silver arm. 'There are pots still in the firepit.'

Uriel nodded, examining the bones before him, wondering who they had belonged to and what malicious twist of fate had seen him condemned to such a death.

'Whoever did this was incredibly strong,' said Uriel. 'The bones are snapped cleanly.'

'Aye, and this one has had its skull ripped from its shoulders.'

'Iron Warriors?' asked Uriel.

'No, I don't think so,' said Pasanius. 'There was a madness to this attack. Look at the stains on the walls. It's blood, arterial spray. Whoever killed these people did it in a frenzy, ripping out throats and tearing their victims apart in seconds. They didn't even have time to arm themselves.'