The Cleansing of the Sin of Damnation was an Imperial military campaign carried out by the Blood Angels Space Marine Chapter in 589.M41, which cleansed the massive Space Hulk Sin of Damnation of a large Genestealer infestation.

Six standard centuries earlier, the Blood Angels had deployed in their entirety to cleanse an unknown Space Hulk in the Secoris System, but unfortunately, they encountered heavier than expected resistance from tens of thousands of Genestealers. Tragically, only fifty Astartes, including future Blood Angels Lord Commanders Kadeus and Dante, would manage to escape the Hulk and survive the massacre.

Six Terran centuries later, a Space Hulk named the Sin of Damnation by the Chapter dropped out of the Warp dangerously close to the Blood Angels' homeworld of Baal. Strike Force Raphael moved to intercept the Hulk, deploying squads of 1st Company Terminators via Boarding Torpedoes. A vicious battle erupted throughout kilometres of tangled corridors, chambers and ducts as the Blood Angels battled furiously against the Hulk's Genestealer infestation. A force of 80 1st Company Terminators, under the command of Captain Michaelus Raphael, eradicated a force of more than 40,000 Genestealers, cleansing the Sin of Damnation and plundering its secrets in the Imperium's name.


Disaster at Secoris

In the year 996.M40, an Imperial Navy patrol passing through the Secoris System detected a large Space Hulk drifting in-system, drawn by the star's gravitational pull. The fourth world of the Secoris System was a populous Hive World, inhabited by more than fifty billion people. It was a hub of commercial and military activity and the threat posed by the closing Space Hulk was immense. Wary of boarding the vessel with his crews, the commodore commanding the flotilla sent an astropathic message to the nearby fortress-monastery of the Blood Angels on Baal. The Chapter responded in full, led by Lord Commander Sangallo, and within three solar weeks, the full might of the Blood Angels had come to Secoris.

The sheer size of the Space Hulk and its proximity to busy trade routes through the system precluded any kind of systematic bombardment -- debris would pose a serious threat to navigation. Instead Lord Commander Sangallo led a full-scale boarding action. The initial stage of the boarding went with little problem, but soon the Blood Angels encountered growing resistance as they attempted to take possession of functioning engine rooms and control chambers. Within thirty solar minutes, Genestealers were rousing from their hibernation in great numbers and Sangallo committed his reserves to bolster the defensive perimeter around the boarding site, leading the reinforcements himself.

BA 1st Co Sin Damnation 2

A Blood Angels Terminator is overwhelmed by hordes of Genestealers.

Unable to secure their objectives, the Blood Angels diverted their attention to the inner areas of the ship, seeking the dormant Genestealers. Their attack only served to hasten the awakening process and soon thousands of Genestealers had encircled the advancing Space Marines. Under the covering fire of the 1st Company Terminators, Sangallo tried to extricate his surrounded squads and was eventually forced to send forward the Blood Angels protecting the landing zone to provide a safe "corridor" back to the boarding craft.

The Genestealers attack relented for a short while and it seemed as if the Blood Angels would be able to withdraw in good order and re-establish their beachhead. However, the calm was short-lived, as the Genestealers had noted the Space Marines' tactics and now attacked to separate them from the ammunition and support personnel at the boarding site. The battle descended into anarchy as some squads attempted to break through to their objective while others fell back towards the Boarding Torpedoes. Divided, the Blood Angels were picked off, squad by squad, swamped by the overwhelming numbers of their foes.

The battle ended when Sangallo had no choice but to order a general retreat. Though kill estimates put the enemies slain at close to 12,000, there seemed an unstoppable tide of the creatures. Of the entire Chapter, only fifty Space Marines, including Captains Dante and Kadeus survived. Kadeus would go on to take Sangallo's place as Lord Commander and lead his Chapter back from the brink of extinction. The action had been a catastrophe for the Chapter. The shame of defeat would last far longer than the losses inflicted.


"Bountiful fate has presented us with the means by which we might repair those wounds upon our souls caused by the weakness of centuries past. It is not only our duty but our right to face the darkness again; to stare into the abyss of the unknown. This time we shall be the cleansing light in the shadow, the burning beacon of righteous war. Restore the honour of the shamed fallen through the death of your foes!"

— Lord Commander Dante, Chapter Master of the Blood Angels

Perhaps it was fate, the will of the Emperor or the machinations of the Chaos Gods, that the Blood Angels were contacted by the Rogue Trader Borrak Vorra, Captain of the Windrush, a little more than six hundred standard years after the disaster at Secoris. By cosmic coincidence, the Rogue Trader had dropped out of Warpspace almost on top of a gigantic Space Hulk only a few light years from the Blood Angels' home system of Baal. When word came of the new Space Hulk the Blood Angels seized the opportunity to redeem their past failure. Under the leadership of Captain Michaelus Raphael of the 1st Company, the Blood Angels sent a task force to intercept and investigate the vessel.

Dubbed the Sin of Damnation by the Blood Angels, the Space Hulk was large, made from the wrecks of nearly a dozen different vessels. Scans performed by the Windrush crew revealed there were high concentrations of alien lifesigns aboard and Captain Raphael treated the entire vessel as hostile territory, suspecting a large Genestealer presence.

Strike Cruisers of the Blood Angels transporting the 1st Company and supporting troops broke Warp close to the Sin of Damnation and launched Boarding Torpedoes. While the Assault Craft blazed through the æther, scanners bathed the vessel with low-power multi-spectral analysis, to provide overall layout data and identify the concentrations of the dormant aliens. Stronger scanners risked alerting the hibernating Genestealers before the Terminators were aboard, so Captain Raphael deployed autonomous reconnaissance devices known as Cyber-Altered Task units, each teleported to a strategic point aboard the Space Hulk to collect vital information.

The scans showed that the majority of the Space Hulk was powerless and lifeless, exposed to the open vacuum of space. The bulk of its vast, chaotic architecture served no function at all. Inside was a seemingly random labyrinth of empty mess rooms, access corridors, dormitories, loading bays, storage chambers, command decks, maintenance bays and other facilities. The haphazard maze was criss-crossed by energy lines, power relays, pipes, cables, communication trunks, venting ducts and other crawlspaces. It would have taken Terran years to clear every last nook and cranny.

Raphael's Strike Cruiser orbited the Space Hulk at a safe distance, their bombardment cannons and torpedoes primed to reduce the Sin of Damnation to atoms at the first sign that the Genestealers were escaping or that the mission was failing. Every warrior was under immense pressure that day; it was a matter of honour that the Blood Angels scoured the Genestealer threat from the Space Hulk and allowed archeotechnologists and other Tech-priests to conduct a full survey of the ancient vessels that comprised it. Anything else would only serve to further crush the Chapter's self-regard, stripping them of all respect and authority. For the sake of the Chapter, Captain Raphael and his warriors could not afford to fail.

Boarding the Space Hulk

"It is our duty to reclaim the past, for only by rightful victory can the blemish of defeat be purged. Six centuries of pain, six hundred years of living with imperfection, and on this day the chance to cleanse our conscience with the flame of the Emperor's wrath."

— Part of the Oratio Penitentiae spoken by First Captain Michaelus Raphael before the Blood Angels' first assault.
Michaelus Raphael

Michaelus Raphael, First Captain of the Blood Angels, recites litanies and benisons of righteous vengeance and contemplates the forthcoming battle.

Closer analysis of the life scan data showed a huge concentration of Genestealers in the cargo hold of an ancient merchantman. Though it was impossible to get anything like an accurate number, due to the low level of the scan and the dormant metabolisms of the aliens, Captain Raphael's technicians informed him that there were at least 40,000 Genestealers aboard, probably more. Any other commander might have baulked at such odds, but not Raphael. He was a Space Marine of the Blood Angels and the pride of his Chapter rested entirely on his shoulders. He gave the order for the Boarding Torpedoes to complete their final approach. The battle would begin very soon.

With painful memories of the Blood Angels' defeat at Secoris, it was decided to commit only the Chapter's Terminators against the enemies aboard the Sin of Damnation. Over long centuries, the 1st Company had been rebuilt and Terminator Armour repaired and constructed. Roughly 80 warriors in total were involved in the fighting, under the command of Captain Raphael, the company commander.

The majority of these Space Marines were organised into five-man squads. With information scarce, Raphael deployed his warriors using Boarding Torpedoes, rather than putting his trust in the vagaries of teleporter technology. Huge missile-like boarding craft blasted through the ether, punching through the outer hull of the Space Hulk. The Space Marines disembarked from their Assault Craft and swiftly established guard positions against counterattack.

With the breach made, a perimeter was established inside while Techmarines and other support personnel could be moved aboard the Space Hulk. This base of operations would be essential to the Blood Angels' success, providing ammunition and ongoing repairs to the Space Marines as they pressed outwards from the landing site.

In order to retain command overview, Captain Raphael remained on board the Strike Cruiser Angel's Sword. From there he was able to pass on strategic objectives to the squads in the Space Hulk, leaving individual missions to the initiative, training and experience of the squad Sergeants. By removing himself from direct fighting, Captain Raphael was able to maintain a degree of strategic oversight that was lacking in the Blood Angels' encounter at Secoris, ensuring that the Space Marines and their support resources were effectively deployed in a hazardous and ever-changing battle.

Cleanse and Purge

BA Termi Sgt vs Genestealers

The Blood Angels begin their daunting task of cleansing the Sin of Damnation of Genestealers

While establishing a beachhead to defend their Boarding Torpedoes, the Blood Angels detected a bank of functioning lifeboats aboard one of the ships that comprised the Hulk. It was a priority that these were rendered inoperable, before any Genestealers could use them to exit the Space Hulk and evade destruction. Though the orbiting the Strike Cruisers had weapons trained on the Hulk to eliminate any escaping craft, such fire would disrupt the Space Marines' operations and was not 100% assured.

The large bank of escape pods was controlled by a central release mechanism located in a control chamber a short distance away. None of the saviour craft were capable of launching until a system override was released on the main controls. Squad Lorenzo was tasked with the mission of destroying the controls completely, in order to prevent the lifeboats ever launching. The control chamber was several hundred metres from the established perimeter and it was Captain Raphael's expectation that Squad Lorenzo would suffer heavy casualties. Such was the importance of containing the Genestealer infestation the commander judged this a price worth paying, even at this early stage of the battle.

With Lexmechanics studying the layout of the Space Hulk and the early movements of Genestealers, Captain Raphael was able to predict the route of the alien attack with some accuracy. The first Genestealer assault was likely to come from the main hibernating cluster, located less than a kilometre from the landing zone. It was imperative that the Space Marines maintained the momentum of their assault rather than be pushed onto the defensive at the very outset.

The expected attack route forced the Genestealers to pass through a key junction where the hulls of two starships had been compressed together. Sergeant Gideon and his squad were despatched to cover the junction and kill all aliens attempting to pass. The first Genestealer assault was effectively countered and the Space Marines were able to expand their perimeter to a position from which they could attack the dormant Genestealers.

As the Space Marines moved into position, the C.A.T. unit closest to the Genestealer concentration had completed its scan of the enemy. However, the sheer density of the Space Hulk's structure prevented the Automaton from transmitting this data and it moved erratically along the corridors as it sought a suitable transmission location. Outside the embattled perimeter, Sergeants Lorenzo and Gideon were in a position to manually retrieve the faulty C.A.T. unit. The two squads converged on the C.A.T. unit's last known position from opposite directions and linked up once it had been recovered. Meanwhile, the bulk of the Blood Angels force pressed out from the landing zone, sweeping aside the alien resistance. Organised and determined, the Space Marines advanced their position by several hundred metres, whilst the Genestealer response was haphazard and ill-coordinated.

With the C.A.T. reclaimed, Squads Lorenzo and Gideon turned back towards the main Space Marine defensive line. Casualties in all sectors had been low and Captain Raphael continued to rotate squads between the primary cordon and reserve to ensure that the Techmarines could affect repairs to damaged armour and re-supply the squads on the firing line.

BA 1st Co Sin Damnation 3

A Terminator Squad cleanses the Genestealer filth with righteous flame.

With the second wave of attacks staved off, Captain Raphael ordered his squads onto the offensive. However, even as the Genestealer attacks lessened in their intesity, a small number of aliens managed to break through the perimeter via an undetected route. Two Techmarines isolated from the other support squads went missing in action. Their Power Armour continued to transmit functioning lifesigns and Captain Raphael quickly organised a rescue response. It was unthinkable that the sacred gene-seed of the Blood Angels should fall into the hands of the Genestealers. With the majority of the force committed to securing the hibernation zone, Raphael once again looked to Squads Gideon and Lorenzo to locate the missing Techmarines. Though Squad Lorenzo located the missing Astartes, they were both sorely wounded, their armour stripped away in many places as blood trickled from large gaping slashes across their bodies. It was too late to salvage their gene-seed, as both had been infected by the Genestealers and the viability of their gene-seed was negative. They were granted the Emperor's Peace by the Blood Angels Terminators' Storm Bolters.

Meanwhile, the data from the retrieved C.A.T. unit showed that the support systems of the merchant ship where the majority of Genestealers were located were serviced from a a single pumping station located near the aft of the vessel. Test releases of toxin gas brought from the Strike Cruisers had demonstrated that it was possible to poison the Genestealers. However, the concentration required was almost one hundred times higher than the fatal dosage for humans. The Blood Angels needed to secure the pumping station in order to flood the merchant ship with gas, and at the same time prevent the Genestealers from escaping once the toxin was unleashed. It was Captain Raphael's intent that a diversionary attack by Lorenzo and Gideon's squads would lure away the majority of the wakened Genestealers. If the enemy could be tricked into thinking a secondary concentration was the Blood Angels' target, the way would be open for the main force to advance against minimal resistance.

During the attack on the secondary Genestealer infestation, contact was lost with the members of Squad Lorenzo. Lifesigns transmitters showed that they had not been killed, while sensorium data revealed that they were in their previous defensive positions but unmoving. As Captain Raphael absorbed this turn of events, he received new information, this time from Librarian Calistarius. Though it remained unclear how Squad Lorenzo had been incapacitated, the effect on the Space Marines' strategic situation was dire. Lorenzo and his warriors had taken a heavy toll on the Genestealer reinforcements but several hundred had survived to threaten the flank of the main attack. Brother Calistarius raced to link up with the outermost Assault Squad, led by Sergeant Leodinus. As the young Lexicanium fought his way towards Squad Lorenzo's last known position, his prescient abilities detected the unmistakable signs of some sort of alien psychic attack that was the cause for Lorenzo's disappearance. Notifying Captain Raphael of his suspicions, Calistarius was then ordered to link up with Squad Leodinus instead, but by the time he arrived, only one Battle-Brother remained alive. The two Blood Angels then proceeded to the last known location of Squad Lorenzo. Squad Gideon completed the purging of their assigned cluster, and also proceeded to move onwards to rendezvous at Lorenzo's position.

The Artefact

BA 1st Co Sin Damnation 1

The Blood Angels fight their way forwards, in order to claim an ancient Chapter relic.

When the Blood Angels finally arrived, Sergeant Lorenzo and his warriors confirmed that they had indeed been subjected to some form of psychic attack by the Genestealers. The exact nature of the threat was indeterminate, but the need to rejoin the main attack was pressing. However, Brother Calistarius detected a strange presence less than a kilometre away, unconnected to the Genestealers. Not wishing to deprive Captain Raphael of all their warriors, Lorenzo and Gideon agreed to split, with the former accompanying the Librarian to investigate this new phenomenon while Gideon returned to the main force. Following the psychic trail, Calistarius and his companions discovered an ancient Blood Angels Battle Barge that had been lost in the Warp nearly nine thousand Terran years earlier. Chapter history attested that the Wrath of Baal had been carrying an important artefact of the Blood Angels from Terra shortly after the Siege of the Imperial Palace had ended. Lorenzo and Calistarius were determined to locate this treasure and retrieve it from the clutches of the Genestealers.

BA Blood Chalice

A Blood Chalice, an ancient artefact of the Blood Angels Chapter.

Within the Chapel vault of the Wrath of Baal, the Space Marines discovered a golden grail, one of the famed Blood Chalices; an artefact of the times before the Horus Heresy. It was stained with the blood of their Primarch and psychic link with Sanguinius coursed through the Blood Angels' veins. Once recovered, the Blood Angels had to fight their way out of the chapel towards the bulk of the main force. Sergeant Lorenzo and Brother Goriel disappeared during the fighting, leaving the squad two warriors down and leaderless. Brother Calistarius took direct command. The main force had been battling hard to contain the Genestealers within the hull of the merchantman, though a few would inevitably escape the cordon. It was imperative that all squads were on hand for the final attack.

Brother Calistarius led the remnants of Squads Lorenzo and Leonidas from the Wrath of Baal, back towards the main force of the 1st Company. They encountered scattered pockets of Genestealers and moved swiftly to rejoin their comrades. However, such was the treacherous nature of the Space Hulk's layout that the shortest route forced them to break through the corridors of a vessel whose emergency doors had closed. As the Space Marines cut their way through the bulkheads, enemy lifesigns closed in on their position. Though they were barely one hundred metres from the rest of the 1st Company, the Space Marines returning from the Wrath of Baal faced two formidable obstacles.

The first was a winding network of corridors and rooms sealed by locked bulkheads. The second was a gathering number of Genestealers that had been attempting to circumvent the cordon set up around the pumping station. Although the artefact had been returned, the Space Marines were still isolated. With the main force unable to break out of their pocket to help Brother Calistarius and his warriors, the Space Marines were left to make their own way through the maze. Squad Gideon had not rejoined the main force, and their Sergeant despatched his warriors to find a path through to their isolated brethren. Having split up to find the most direct route, both squads were in a poor defensive position to respond when the Genestealers located them and began to close in for the kill.

On the Defensive

1st Co. Terminators Space Hulk

The Blood Angels 1st Company fight a desperate battle against hordes of Genestealers.

Though suffering increasing casualties, the Blood Angels Space Marines had fought hard and the majority of emerging Genestealers were contained within the hold of the merchant ship. Techmarines had jury-rigged large vats of the toxin gas to the atmospheric control systems at the pumping station. Captain Raphael expected a strong response once the gas started pumping and had arranged two lines of defence between the aliens and the means of their demise. The first was a cordon of squads directly around the hold; the second comprised the survivors of Squads Gideon and Lorenzo, who protected the pumping station directly.

The mess of hastily connected pipes and ducts in the pumping station was unstable. To ensure that they remained operational, the Space Marines defending the control chamber were ordered not to fire heavy weapons into or out of the pump room for fear of damaging the toxin vats. With a thrum of power generators, the pumping station was activated. The Techmarines withdrew from the line of battle and the Space Marines prepared for the inevitable assault. In the hold below, the deadly gas began to sweep through the ventilation shafts. The Genestealers' lair was a spacious artificial cavern and it would take some time for the toxin to build up to deadly concentration. Detecting the encroaching gas, the Genestealers began to wake more swiftly, roused from their biostasis by the threat. Soon, more than a thousand aliens were bursting from the ship's holds towards the Space Marines.


BA Cleanse Hulk

Surrounded on all sides, the Blood Angels desperately fight their way to their extraction point.

While the remaining Blood Angels fought a desperate battle against the neverending hordes of attacking Genestealers, the toxin attack proved to be a success, and all but a few hundred Genestealers had been eradicated. The surviving Space Marine squads swept the Genestealer lair for the remaining aliens and fanned out into nearby sectors to hunt down those that had escaped before the gas was released. Sergeant Lorenzo had reappeared after fighting his way back alone from the Wrath of Baal. He reported encountering a different kind of Genestealer, larger and faster than the others.

Between the psychic sense of Brother Calistarius and a deep probe scan from the orbiting Strike Cruisers, the Blood Angels were able to locate two more creatures like the one that had attacked Lorenzo. Raphael ordered Lorenzo and Calistarius to take tissue samples from these aliens for future analysis, and then destroy them before they awoke. Sergeant Lorenzo pulled together an ad hoc squad from the most battle-ready survivors of the fighting. The squad was issued with portable power field generators to aid them in their mission. These could be used to close off doors and passages for a short space of time, ensuring that their prey would not escape. What Lorenzo did not know at the time was that the creature he had followed through the underbelly of the Hulk was now stalking him.

Brother Calistarius vs Broodlord

Brother Calistarius locks mind with the sole remaining Broodlord in a deadly psychic duel.

Lorenzo was successful in destroying two dormant Broodlords, as the Blood Angels had dubbed the Genestealer leaders. During the encounter, Brother Zael sacrificed himself to save the Sergeant and the active Broodlord was driven off, believed dead. Isolated from the main force, the survivors of the mission were now at the heart of a rapidly converging circle of Genestealers intent upon destroying those that had slain their leaders. There was no chance of relief squads from the main Blood Angels force reaching Lorenzo and his comrades in time. Following the readings on their sensorium, the Space Marines fought their way towards the exit.

Their objective was a service shaft that led out onto the surface of the Space Hulk from where they could be extracted by gunship. The tissue samples carried by Lorenzo were an important source of information about the Genestealers and needed to be returned at all costs. A few dozen metres from their escape, the Space Marines came across a collapsed deck. Under increasing attacks from the Genestealers, they had to negotiate their way across the wreckage and reach the external duct. To make matters more difficult, the Broodlord Lorenzo thought destroyed was anything but dead, and intent on tearing apart the enemies that had destroyed its brethren.

In the end, it was only through the sacrifice of his fellow Battle-Brothers that Brother Calistarius was able to fight his way to the Hulk's surface and signal command from an extraction by Thunderhawk gunship. He successfully obtained both the genetic sample and the ancient Chapter relic, but only at the expense of his brothers' lives. This small force of eighty 1st Company Terminators managed to eradicate a much larger force of more than 40,000 Genestealers, cleansing the Sin of Damnation and enabling its secrets to be plundered in the Imperium's name. But more importantly, they had avenged a long-standing stain to their Chapter's honour.


  • Codex Adeptus Astartes - Blood Angels (8th Edition), "A Chronicle of Heroes", pp. 20, 51
  • Space Hulk: Missions Book (3rd Edition), pp. 2-33, 42-45
  • Space Hulk: Missions Book (2nd Edition), pp. 7-20
  • Warhammer 40,000 Compilation (2nd Edition), pp. 88-115
  • Warhammer 40,000: Rogue Trader (1st Edition), pg. 211
  • White Dwarf 113 (UK), "Space Hulk" by Richard Halliwall, pp. 29-34
  • Sin of Damnation (Novella) by Gav Thorpe
  • Sanguinius Irae (Short Story) by Gav Thorpe
  • Space Hulk (Board Game) (3rd Edition)
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