The Hereticus gave me a job to do,' replied Thaddeus, his voice raw and painful in his throat. 'Any inquisitor would have done the same.'

Kolgo shook his head, almost sadly. 'Our mistake was both underestimating and overestimating you, Thaddeus. Underestimated because we thought that your skills were not yet well developed enough to allow you to pursue the Soul Drinkers as closely as you have. Overestimated because we thought you would be quicker to develop a sense for the consequences of your actions. The Inquisitorial remit is theoretically limitless, but Thaddeus, for the Throne's sake - Pharos? After I told you how delicate our situation with the Mechanicus was. The damn place only blew seventy-two hours ago and already sub-battlefleet Aggarendon has lost three ships to the withdrawal of tech-priest support. Ordi-natus units on Calliargan and Vogel are about to fall silent. The Mechanicus are convinced that Teturact somehow got at Pharos and the tech-guard presence there has been tripled.’

'You have your objectives, Kolgo, I have mine.'

'Ah yes, the Soul Drinkers. Presumably you know why you were given the task of tracking them down.'

'Because I could do it. And because I work differently from Tsouras.'

Kolgo reached up to the life signs machine and made an adjustment. The medi-gauntlets around Thaddeus's hands cracked open and there were several pinpricks of pain as the sensors and needles were withdrawn. Warmth seeped back into Thaddeus's body and he felt he could move again - he flexed his fingers and arms, and gradually sat up. He was aching and tired, but there was no more pain than there should be.

'We chose you, Thaddeus.’ said Kolgo with an unforgivable twinkle in his eye, 'because we knew you would fail. We knew you would keep your distance, tailing the Soul Drinkers and gathering information without actually striking. You are a watcher, Thaddeus, a listener. A good one, too. But not a victor.’

You didn't want them stopped.'

'Oh, we did. I and the inner circles of the Ordo Hereticus recognise the Soul Drinkers as a grave threat and it is entirely our intention to corner and destroy them. But not just yet. Think about it, Thaddeus. We estimate the Soul Drinkers Chapter is between half and three-quarters strength, with no chance of reinforcement. That gives us a maximum of seven hundred and fifty Space Marines with barely a handful of surviving Chapter serfs if the evidence from the scuttled fleet is anything to go by. My household's own staff numbers more than three times that. The storm troopers attached directly to my command outnumber the Soul Drinkers tenfold.

'Space Marines from preachers' sermons can take on entire armies on their own but the truth is rather different. Without the support of other Imperial forces, or hordes of cultists or secessionists, or legions of daemons, they are alone and vulnerable. There is no point being the head of the spear if there is no haft or driving hand to back you up. The Soul Drinkers are dangerous but compared to someone like Teturact, they really are of little consequence. And there are many creatures like Teturact loose in the galaxy, I am afraid to say.'

'So you sent me after them because they aren't important.’

'On the contrary, Thaddeus. They could be very important. Regardless of the truth,. Space Marines are legends. Traitor Marines are a nightmare. There is something so inherently heretical in the very concept that it carries with it far greater power than the actual Marines in question.’

Thaddeus should have felt betrayed and used. But he felt neither in particular - he just felt small, like a tiny wheel in a huge machine. It was a strange, dry feeling, as if his blood had been drained and replaced with dust. All his life he had worked for the Inquisition, battling against the vastness of the galaxy in a quest to make a difference. But now, with Lord Inquisitor Kolgo sitting next to him and explaining how he was just a pawn in better men's games, the galaxy seemed vaster than ever.

They are a weapon.’ said Thaddeus, his voice tired. 'A political weapon.’

Kolgo smiled, almost like a father. 'I knew you would realise it eventually. It surprised me you didn't get it more quickly The Soul Drinkers are political capital - an enemy with the symbolic power of a renegade Chapter is not to be destroyed lightly. There will be times when the Ordo Hereticus must fight its corner against the rest of the Imperium, for the Imperium is almost as likely to harbour enemies as the ranks of the heretic and the alien. When that happens, we need the power of such symbols to prove our worth in the eyes of the lesser-minded of the Emperor's servants. The Soul Drinkers are to be destroyed when it would bring us the most benefit, and when that time comes we will bring more and better minds to bear than yours.'

1 understand.’ said Thaddeus. 'I am expected to track the Soul Drinkers but not to move on them until you give the word.'

'It will be a long time before you really understand.' Kolgo stood up and, as if on command, a pair of valet servitors trundled in, their low bodies sprouting long, thin manipulators that held the simple, dark leather bodyglove and blastcloak of an interrogator. 'You will be taken back to the fortress at Caitaran and reassigned. We need competent minds like yours in the warzone. The trip will take about three weeks - I'm afraid I can only offer clothes such as these and few comforts, I keep a very simple ship.’

'The data I collected. It was in a data-slate in a pocket of my HE suit. Do you have it?'

'Everything you were wearing was lost. Only your sidearm was robust enough to survive. A very nice piece, if I may say, particularly the ammunition. I have it in my armoury here.’

'No matter.’ said Thaddeus, hoping Kolgo couldn't tell when he was lying. 'It didn't contain anything important.’

But in a way it was true. Thaddeus only remembered two names from the reams of data he had salvaged, but they were the most important information of all. The first was Karlu Grien, a Magos Biologis who was the only surviving adept to have worked in a certain isolated genetor facility. The second was the name of the facility itself: Stratix Luminae.

SEPTIAM CITY BURNED. The Gathalamorian artillery had lobbed incendiary charges into the presumed hotspots of defenders - the palace quarter, the senate buildings, the Enforcement Division barracks -and raging firestorms had engulfed the flammable hovels that crowded against the city's once-grand buildings. But far worse were the fires the defenders themselves had set. They didn't need to breathe as normal men did, so tottering piles of plague dead were lit to fill the streets with banks of greasy stinking smoke. Ammunition and fuel dumps were rigged to blow and the first elements of the Stratix XXIII through the defences to the north found themselves in a nightmare of booby-traps and flaming debris. The Jouryans entered through the southern quarter, which was composed of the more spacious gardens and townhouses of Septiam Torus's middle classes, so they moved faster and further when the breaches were taken.

At their head were their unexpected allies, the Space Marines who had arrived at the largest breach at the critical moment and punched through the defences like a dagger. Few Jouryans asked what had happened to the crews and medics of Squadron Twenty - all they saw were purple-armoured warriors a head taller than any Guardsman, who charged ahead with insane speed and seemed almost desperate to come to grips with the enemy face to face.

The Stratix XXIII found themselves bogged down in the sprawling dwellings to the north. The homes of dead soulfire harvesters became room-to-room battlegrounds where dug-in weapons teams shredded Stratix troopers at intersections and in open spaces, where tripwires rigged with demo charges blunted assaults long enough for the Septiams to counter-attack.