LIKE MOST OF the rest of the Imperium, no one really knew when Koris XXIII-3 had been settled. The grey-green, mostly featureless world had supported continent-spanning grox farms for longer than the Administratum could accurately record. The agri-world supported barely ten thousand souls, but was a subtly critical link in the macro economy of the systems that surrounded it, for grox formed a commodity as vital as guns or tanks or clean water.

Grox were huge, lumbering, reptilian, unsanitary and foul-minded. Crucially, however, they were almost entirely edible, each producing a mound of colourless, tasteless, stringy but nutritionally sound processed meat. Without the grox that were lifted from Koris XXIII-3 in vast-bellied cargo ships every three months, the billions of workers and gangers on the nearby hive worlds would starve, riot, and die. The shipyards of half a segmentum would find their human fuel faltering.

The Administratum knew how important the grox were. They administered the agri-world directly, circumventing tax-dodging governors and grafting private enterprise by keeping their own adepts as the sole power and, indeed, the whole population.

Very little of interest happened on Koris XXIII-3, a situation the adepts of the Administratum had worked hard for. The roaming herds of grox and the small islands of adept habitats went centuries with scant incident, the passing years marked only by the arrival of the huge dark slabs of the cargo ships and the occasional desultory deaths, births and promotions amongst the handful of humans.

So when a ship actually landed at the planet's only spaceport at Habitat Epsilon, carrying something other than another adept to replace a stampede death, it was a rare event. The ship was small and very, very fast, mostly composed of a cluster of flaring engines that tapered to a sharp wedge of a cockpit. There were no markings and no ship name, whereas an Administratum ship would bear the stylised alpha of the organisation. Adept Median Vrintas, the highest-ranking adept in the habitat, guessed that the ship carried someone or something important. She quickly donned her black formal Administratum robes and hurried across the meagre, dusty streets of the habitat to greet the ship's occupant.

She didn't know how right she was.

Habitat Epsilon, like every other structure on the planet, was formed of gritty brown rockcrete, pre-moulded and dropped from low orbit. The buildings were ugly and squat, the architecture featureless and windowed with dark reflective glass that kept the glare of the orange evening sun from the offices, workrooms and tiny living quarters. The spaceport was the only feature that made Habitat Epsilon remarkable, a prefabricated circle jutting from the edge of the habitat. There was a small unmanned landing control tower and a few unused maintenance sheds, indicative of how very few ships landed there.

A section of the ship's hull lowered with a faint hiss of hydraulics. Feet tramped down the ramp and three squads of battle-sisters marched out. Soldiers of the Ecclesiarchy, the church of the Emperor and the spiritual backbone of the Imperium, they wore ornate black power armour that clad them from gorget to foot and carried enough firepower in their boltguns and flamers to reduce the habitat to smoking rubble. Their leader was more stern-faced than the rest of the Sisters, and old in a way that suggested she was a damn good survivor. She bore a huge-bladed power axe. The armour of the Sisters was glossy black with white sleeves and tabards - order and squad markings had been removed.

The sister superior said nothing to Adept Median Vrintas as the Sisters of Battle filed out onto the spaceport's ferrocrete surface. They flanked the ship as an honour guard, weapons readied - as if anything in Habitat Epsilon could threaten them. Adept Vrintas had heard of the Sisters of Battle, of their legendary faith and skill at arms, but she had never seen one of them in the flesh. Was this some priestly delegation, then? The Missionaria Galaxia, or a confessor come to see to the planet's spiritual health? Vrintas mentally congratulated herself on having the habitat's small Ecclesiarchy temple swept out just three days before.

The next figure to emerge from the ship was a man. He was not particularly tall but his considerable presence was aided by the carapace armour that covered his torso and upper arms and the floor-length blast-coat of brown leather lined with flakweave plates. His face was long and lined, his jaw pronounced and his nose slightly lumpy as if it had been broken and set a few times. His eyes were a curious greyish blue, larger and more expressive than eyes set in that face had a right to be. His black hair was starting to thin. Subtle implants in one temple and behind the ear were for neuro-jacks, simple as far as augmetics went, but far beyond the means of any planet-bound adept. His hands were gloved - one held a data-slate.

He strode past his honour guard of Sisters, glancing at the sister superior with a barely perceptible nod. The watery sunlight of Koris XXIII-3 glinted off the rings on his free hand, that he wore over the black leather glove. The stiff breeze fluttered the hem of the blastcoat.

'Adept?' he asked as he walked up to Vrintas.

'I am Median Lachrymilla Vrintas, the chief adept of this habitat,' said Vrintas, tingling with the realisation that this visitor must be far, far more important than anyone she had ever met before. 'I oversee the planet's second most productive continent. We have five hundred million head of grox in nine...'

'I am not interested in the grox.’ said the stranger. 'I ask only a few hours of your time and access to one of your adepts. There need be minimum disruption to your important work here.’

Vrintas was relieved to see a subtle smile on the man's face. 'Certainly.’ she said. 'I shall need to know your name and office, for the records. We can't have just anyone wander around our facilities. And of course you and your colleagues will need to walk through our disinfectant footbaths. There will be quarantine protocols if you wish to leave the habitat as well, so once I know under whose authority you are acting...'

The man reached into his blastcoat and took out a small metal box. He flipped open the lid of the box and inside Vrintas saw a stylised T of gleaming ruby in a silver surround. 'Authority of the Emperor's Inquisition.’ said the man with the same smile. 'You need not know my name. Now, you will kindly direct me to Adept Diess.’

INQUISITOR THADDEUS was an extraordinarily patient man. It was this quality, above all others, that had kept him doing the Inquisition's work when men more violent, or brilliant, or strong-armed had found themselves lacking. The Ordo Hereticus, the branch of the Emperor's Inquisition that rooted out threats amongst the very men and women it was sworn to protect, needed all those qualities. But it also needed the understanding that the Imperium could not be healed of all its sicknesses at once.

It needed men who could see the enormity of a task that stretched well beyond their own lifetimes, and not give way to despair. Thaddeus knew that, as just one man, even with the magnitude of the resources he could command he could do but little in the grand scheme of the Imperium and the divine Emperor's wishes for mankind. At present he had a full company of Ordo Hereticus storm troopers and several squads of battle-sisters under Sister Aescarion, but he knew that even with their guns he could not hope to end the corruption and incompetence that threatened the Imperium from within - just as aliens and daemons threatened from without. The whole Inquisition had that responsibility. If the task was ever to be finished, it would be finished by men and women of the Ordo Hereticus, many generations distant.