'Your own?' Omegon asked.

'The Legion's.'

'And...?'

'I fear we have taken a wrong turn, my lord,' the Librarian said with a pained expression. 'Or that we soon will. Our current path takes us to a dark place.'

Omegon nodded. He understood all too well what Echion was saying.

'Have you spoken of this to anyone else?' Omegon asked.

'Of course not,' Echion replied. 'The Librarius was formally disbanded, but for the requirements of specific missions and assignments. The legionnaires under my command are not aware of my gift.'

'What about your former master, the Chief Librarian?'

'No. I confide only in you, Lord Omegon.'

'And I am listening, brother. I do not doubt your capabilities, enhanced under these special circumstances. I fear, however, that you glimpse the journey and know not the destination. Trust in this: there are many futures, many eventualities, many paths that the Alpha Legion might take. It is our enemies' failing to see only what is presented to them in plain terms. Their undoing is to be blind to our myriad methods. Let us not make the same mistake. You can rest assured that Alpharius knows the darkness you have witnessed and has seen the light beyond. If we stay true to one another, to the purpose for which we were all created and to the principles upon which our Legion was founded we will find the light together. We will achieve enlightenment. We will secure the ultimate victory.'

Echion bowed his head. 'I thank you for your confidences, my lord.'

'And yours, Master Echion. I shall expect Commander Janic's triple-coded transmission shortly. Now, if you'll excuse me, I have matters of equal gravity to attend to.'

'Of course. Hydra Dominatus, Lord Omegon.'

'Hydra Dominatus.'

The hololithic display crackled to a static miasma and then blinked into nothingness above the display tablet. Omegon stood framed by the deep darkness of the lancet port.

A voice came from the shadows. 'He's going to be a problem.'

Sheed Ranko emerged from the rear of the chamber, and strode around the breadth of the table. He was a hulking warrior almost as big as Omegon himself and captain of the Lernaean Terminator squad, and master of the strike cruiser Upsilon. An honoured veteran and gifted tactician, he had been at the twin primarchs' collective side since the Legion's first irregular conquests of the Great Crusade. 'I mean it,' he said again. 'Echion's going to be a problem.'

'Or the solution to one,' Omegon mused. Ranko joined him by the viewing port.

'As much as I enjoy sitting in on your status reports,' the captain said, 'I presume you grace the Upsilon with your presence because you need something.'

Omegon gave him a thin smile. 'A favour. The advice of an old friend. Nothing you haven't done for me a thousand times before.'

'I serve your interests,' Ranko told him, taking a throne at the obsidian table and indicating for the primarch to do the same.

'And I the Legion's, captain.'

'Where's Alpharius?'

'Returning from council with the Warmaster,' Omegon told him honestly. 'He's assembling the fleet. I expect the Upsilon will receive her orders soon.'

'You are here on his behalf?' Ranko asked.

'In his interests, yes.'

'Then what can I do for you both, and the Legion?'

'Before I tell you, I need you to understand something, Sheed,' Omegon said, fixing the veteran's gaze. 'Legion operations always require a certain degree of secrecy and discretion.'

'Yes.'

'This goes far beyond that,' Omegon said simply.

'Fair enough,' Ranko replied, intrigued. 'Want to tell an old friend why?'

'I'm mounting a sensitive operation.'

'All Alpha Legion operations are sensitive.'

'And none more so,' Omegon spoke in hushed tones, 'than when you are infiltrating your own Legion.'

Ranko stared grimly at him.

'No one knows the Legion like you,' the primarch continued. 'No one has operational experience across as many theatres. You've seen many of them prosecute their duty under fire. All Alpha Legionnaires are exceptional, but I need legionnaires not only of singular talent but also of a very specific disposition. It's going to get... confusing.'

'You want recommendations.' Ranko said, matter-of-factly. Gone was the warrior wit and the pleasure of seeing an old friend. This was something else entirely. 'It would help if I knew a few details of the operation, so I can gauge exactly what it is you need.'

'I'll have them shortly,' Omegon replied.

Ranko looked from the primarch to the hololithic tablet, and back to Omegon again.

'You're going to hit the Tenebrae installation?'

Omegon nodded. 'My informants and astrotelepathic intercepts have detected a leak.'

'Within the Legion?'

'Yes. Sensitive data and information relating to the placement of Alpha Legionnaires and operatives, on both sides of the conflict.'

'I don't believe it,' Ranko said. 'I mean, I do, obviously. But how is this possible?'

'This is a civil war,' Omegon reminded him. 'There are those placed among the Legions loyal to the Emperor who secretly supply the Warmaster with intelligence and appropriated materiel. Why not the other way round?'

Ranko continued to marvel in disappointment and disbelief. 'Because this is the Alpha Legion, lord.'

'A fact of which I am painfully aware,' the primarch sighed. 'I have been monitoring the situation, of course, in the hope that the leak could be identified and neutralised. That was until Alpharius's own safety was almost compromised.'

'Alpharius?'

'A rendezvous from which he had to promptly withdraw,' Omegon said. 'Whoever they were, whether they fought for the Emperor or the Warmaster... they could have taken my brother right then and there.'

'And you traced it back to Tenebrae?'

'A partially decrypted astrotelepathic message, originating from the base,' Omegon confirmed. 'Times and movements. They knew exactly where and when to strike.'

'Echion, then.'

'Possibly. The Octiss System. It's one of the few outlying regions uncompromised by warp storms. You heard him yourself the Pylon Array calms the immaterium. An astrotelepathic message might reach Ancient Terra from there.'

'How is Alpharius taking it?' Ranko asked.

'Spitting venom, as you might expect. We have no time to investigate. The war moves apace. We do not have the luxury of tracking this back to an enemy sponsor, not when even our attempt to do is likely to be reported. Tenebrae is compromised. It must be destroyed leak and all before knowledge of the array or even the installation itself falls into the hands of another Legion.'

Ranko placed a hand upon the table. 'You need legionnaires, then, who can infiltrate an Alpha Legion base and will not question the order to kill their brothers. Many of whom they will know to be innocent.'

'Yes.'

The captain paused for a moment, soaking up the enormity of the task.

'Then you need Goran Setebos Sigma Squad, 3rd Company. His team were responsible for hitting the matrix outpost on Oblonski's World. Setebos is pretty cold, even for the Legion, but if it's victory over everything else, then he will do what needs to be done.'

'Where is he currently deployed?'

'Running interference on the 915th Expeditionary Fleet, I believe.'

'Thank you, Sheed,' Omegon said.

'You're also going to need a psyker,' the captain continued, 'and you can't just pull one from the Legion in all likelihood, Ursinus Echion will have had some role in their training.'

'An operative then?'

Ranko shrugged. 'The question is, who? To go up against Echion, you are going to need someone really special. The problem is, the more special they are, the more dangerous they are to everyone else.'

'You don't always have to fight fire with fire,' Omegon muttered, then seemed to reconsider. 'No readers. No telepaths. There's problem enough with leaked information.'

'Agreed.'

'You have a suggestion?' the primarch asked.

'Perhaps,' Ranko said. 'We've been decoding transmissions from the Black Ships that Echion mentioned. The same name keeps cropping up. Successive Sisters of Silence cadres have failed to capture a witchbreed called Xalmagundi on the hive world of Drusilla.'

Omegon nodded. 'Sounds promising. Any other advice?'

'Echion and Commander Janic are going to have that installation wrapped up tight,' the captain insisted. 'You're going to need someone on the inside.'

'I already have a candidate in mind,' the primarch assured him.

Ranko nodded.

'Has it really come to this? Our own Legion?'

'With treachery in our midst, we cannot falter,' Omegon said. 'Traitors, wherever they are found, must be dealt with decisively. Sacrifices must be made.'

Omegon crossed the oratorium and took a pair of chalices from a tray. He offered one to Ranko. 'Thank you for your assistance with this, old friend. There are few to whom I could turn with this.'

'At your service, always,' the captain said, raising the chalice for a toast. 'To mission success, and to necessary sacrifices.'

The pair drank. Ranko pulled the rim from his lips thoughtfully. He found himself looking down into the depths of the chalice.

'You know what that is?' Omegon asked.

'Yes, my lord,' the captain answered after a moment.

'Then you know what it is that I ask of you.'

Ranko downed the rest. 'What you ask of us all,' the captain said. 'Everything.'

BETA.

Operatus Five-Hydra: Elapsed Time 3/-734.29//CHOPhemus IV Tharsis Heights The planet was slowly turning itself inside out, though Phemus IV had been quietly raging for millennia. A crepuscular ball of igneous rock and soot storms, it was covered in a rash of volcanic eruptions. Cracked through with glowing fractures, it resembled a celestial bauble that had been dropped and was about to shatter.

The only creatures to make their homes in the Phemusian nightmare were migrant tribes of greenskins that routinely roamed the lava-dashed landscape in order to avoid seasonal eruptions. Sergeant Goran Setebos only knew these tribes by the banners they carried and the crude symbols painted on their corrugated hovels. Squad Sigma had ascribed names to the tribes based upon the scrawled iconography: the Spumers; the Green Devils; the Scorchers; the Magmatusks; the Fireball Clan.

For the past month, the Alpha Legionnaires had been engaged in a war by proxy. They had not killed a single greenskin or even discharged a single round from their soot-smeared bolters. They were shadowing a far more dangerous prey across the volcanic highlands, razorblade canyons and dismal basalt plains.

The V Legion.

The Khan's swift savages. The infamous White Scars.

Black rock crumbled in Setebos's grasp. If his palm hadn't been protected by the ceramite of his gauntlet, the remaining shard of glassy rock would have pierced straight through. The sergeant was clinging to a rockface, punching handholds and toe-picking his way up the midnight crag. Beneath him, the nine other members of Squad Sigma followed up through his improvised purchase points. Glooping beside them was a sluggish lava fall, a slow-moving torrent of molten rock that bathed the armoured legionnaires in the perpetual heat of a furnace.

At the top of the escarpment, Setebos unlocked his bolter from his belt and crunched through the gravel of a volcanic crater. Magma had eaten through the rim to create the falls and Setebos chose his footing carefully around the bubbling margins. One by one, the Alpha Legionnaires made their way over to the far side of the crater, their grimy plate glinting in the fiery glow.

'This looks good,' he said. 'Isidor.'

Legionnaire Isidor consulted a scuffed and scorched data-slate, turning it and his armoured form around to match their most recent relief maps with the surrounding topography. He gestured east with an outstretched gauntlet.

'If the Fireballs haven't started moving by now,' he announced, 'this should light a fire under their monstrous arses.' He handed the slate to Vermes, who counter-checked his cartography.

'This channel should then join with the one from this morning,' Setebos murmured.

'Affirmative.'

The whole squad remembered all too well the channel they had crossed with some difficulty a few hours before. Braxus had almost pitched into the hellish river of molten rock.