"It requires more than flame to eliminate that taint. Only time and purification can prevent this darkness from spreading."
- —Watch Captain Carlsworth
The planet has been badly contaminated and influenced by the forces of Chaos. Over the last few millennia, a world that was once believed to be a jewel in need of refinement has been transformed into a near-worthless lump of rock.
Those who continue to live among its ruins bear the marks of this destruction as contamination upon their flesh and souls. Yet in spite of this, there are those who believe that the world may yet hold tremendous hidden value.
Belissar continues to bear mysteries for the Imperium. Even now, a few questions of any potential value are outweighed by the substantial risk such a contaminated world represents.
Until those are better resolved, the Deathwatch believes that it must be observed and guarded rather than destroyed in the interests of security.
At the height of the ancient Jericho Sector, Humanity's successes were paramount. The civilised worlds were unable to contain the region's bounty. Mankind outgrew the sector's established worlds and began to colonise any worlds that seemed likely to contribute to its wealth.
Those planets well-suited to agriculture were selected in particular, as several of the Hive Worlds were extremely dependent upon the import of foodstuffs.
Records from this era are fragmented. After Verronus collapsed, there was no local surviving repository of data from the Jericho Sector, and few of the local records were ever transferred to blessed Terra. Most records have been scavenged and inferred from the few ancient reports that survive.
Oral traditions of Imperial colonial worlds, including Belissar, are often contradictory and inconsistent. As a consequence, little of this information can be confirmed as fact. Bearing that in mind, it is believed that the colony on Belissar was founded in the late 33rd Millennium.
A younger son of one of Verronus' noble lines chose to establish the colony, using a combination of Imperial resources and mercantile investments. It is clear that someone with influence and significant resources took a direct interest in the colonisation process.
Some of the ancient legends indicate that members of the Adeptus Mechanicus were directly involved as well. These suggest that followers of the Machine Cult agreed to aid the world's agricultural development. Unfortunately, the precise nature of this development is unclear, and different legends contradict one another.
The most likely conclusion is that substantial changes were made to the planet's atmosphere at the same time as several native plant and animal species were eliminated in favour of species adapted from Holy Terra.
For many of the worlds of the lost Jericho Sector that fell from grace, the reasons are complex and unclear. This is not the case for Belissar. Simply put, the colony had not become self-sustaining prior to the sector's collapse. The world's civilisation was entirely dependent upon imported goods and technologies.
Their agricultural facilities enabled the world to provide ample foodstuffs for its populace, but even these assets required maintenance from experts who only visited irregularly.
Without a capable support network, the colonists were unable to maintain their technological base. In short order as the sector's Age of Shadow began, the population fell to infighting as all became more and more desperate for life's basic necessities.
After thousands of Terran years of isolation, there were few survivors upon the world. Those that remained were struck by an even greater tragedy during the latter years of the 40th Millennium. Shortly after its manifestation, the Hadex Anomaly was prone to fitful movement and expansion.
During a time of ill-portent, Belissar was swallowed by the Warp rift. After more than a century, the Anomaly moved into a different portion of the sector, and the planet emerged from the Warp, though horrifically changed.
In 222.M41, Deathwatch and Ordo Malleus forces committed to a joint effort termed the "Belissar Suppression." The intent was to cleanse the planet of its Warp contamination, so that this hideous taint might be removed from the galaxy. Many of the field reports from that action have been permanently sealed.
It is believed that the worst of the daemonic influences were eliminated from Belissar's surface. However, it is clear that the effort could not be deemed a triumph. The Warp's taint lingers upon this world, and none can say what measures might be taken to fully cleanse it.
End of the 41st Millennium
In spite of the best efforts of Inquisitorial forces, Belissar remains a world that has been severely contaminated by direct and extended exposure to the Warp.
Unholy creatures from the Immaterium still maintain a strong hold upon the world and their influence is present everywhere. Descendants of the Imperial colonists now worship these foul creatures as cultists in servitude to the Ruinous Powers.
Both physical mutations and extreme mental aberrations are common hallmarks of these unclean individuals. It is improbable that there are any surviving Humans who could return to the Imperium's fold.
Despite this deep-seated corruption, Belissar's isolated position, far from other worlds of the Jericho Reach, has kept it largely safe from a full Exterminatus action, though the Ordo Malleus has insisted on a strict quarantine to enforce that isolation.
After the events of the Belissar Suppression, the Deathwatch swore an oath to continue to oversee the world. Kill-teams are dispatched at least once a solar decade to investigate the world's contamination level.
They are not expected to seriously attempt to cleanse the world of its Warp taint -- a monumental task even for the Deathwatch. Instead, they are tasked with the responsibility to keep this contagion from spreading.
To date, most believe that their efforts have been successful. However, some argue that this ongoing contamination represents an unacceptable risk, and argue that more extreme measures must be taken.
There are no other colonised worlds near Belissar, nor are their significant Warp anomalies in the region. The world is far from the front of the Achilus Crusade, so it is unlikely to directly interact with the Imperium for some time.
A few Inquisitors among the Ordo Malleus believe that this isolation presents an unusual opportunity for them to study the unholy. There are rumours that at least one Inquisitor visits the world even more often than the Kill-teams.
If this is true, the precise motivations for the visits are unknown and extremely worrisome. Extended exposure to this level of Warp corruption, even in the name of the Imperium's defence, might shatter the mind of even the most stalwart individual.
Ancient records and legends indicate that Belissar's atmosphere was once fully breathable and hint that it may even have been pleasant. While that may have once been true, this is no longer the case. Toxic compounds now flood much of the planet's atmosphere, water, and surface.
These represent a substantial hazard to any Humans who might visit the world. The poisons are also one of the key factors for ongoing mutations among the cultists who continue to inhabit the world.
In some regions, the toxins are so dense that they hang as a thick fog over the world's surface. The massive clouds are visible even from the void. Deathwatch tracking systems indicate that some of these clouds have been in existence for nearly a solar century, occasionally migrating but never dissipating.
Within the clouds, filtration systems are necessary for breathing and vision enhancement is essential for any sort of navigation. Travel through these regions represents a significant risk, even for Space Marines, and must not be undertaken lightly.
At times, these toxic clouds form into complex weather patterns, often due to interactions with other nearby pollutants. The resulting storm systems can be deadly -- not only from the wind shear and blinding rain -- but also from the incredibly corrosive nature of these elements.
Belissar's unstable nature makes predicting such catastrophic events nigh-impossible. The storms erupt spontaneously and sometimes dissipate just as inexplicably.
Even more dangerous contaminants possess other portions of this foul planet. The taint of Chaos has warped not only the world's inhabitants but the very essence of Belissar.
There are countless enclaves of the Warp-spawned remaining on this world far from the Hadex Anomaly. The majority of these locales are made up of decidedly unnatural geographic features. The very surface of the planet may act against any who dare to tread upon it.
In some such places, the planet looks and acts like a living being. Ground has become flesh and massive hairs, feathers, or scales sprout from its surface in place of foliage. In a few places, the surface flows with blood and bile, creating loathsome rivers and lakes.
The unholy Warp-spawn that inhabit such locations sometimes take on physical appearances that are consistent with these places -- or it might just be a manifestation of the land itself.
Kill-teams that have travelled into such "living" regions report attacks by creatures that resemble massive immune cells and mouths that spontaneously form and open before attempting to devour their battle-brothers.
Other regions, which first appear comparatively mundane, exhibit a more subtle Warp contamination. Such locations appear to be relatively clean of toxins and even exhibit signs of native flora. Closer examination inevitably reveals that the land itself is alive. The planet's raw materials come to life and attempt to destroy intruders.
Even a sacred bolter has limited efficiency against a cliff that makes a deliberate effort to collapse upon a Space Marine. Records suggest that regions such as this are most easily identified by their lack of visible pollution, but this is hardly a reliable benchmark.
Deathwatch forces believe that Belissar's inhabitants are effectively isolated. There is no indication that they are capable of constructing a void-capable vessel nor have watch-satellites shown any indications of Warp-capable craft entering the system.
While they continue to oversee the world's security, the Deathwatch only commits to sporadic involvement with its surface. Consequently, the battle-brothers possess only limited records about the known population. Even though the planet represents a significant danger, that threat is mitigated by its isolation and by requests from the Ordo Malleus to maintain its isolation.
It is believed that there are numerous tribal populations active upon the planet. Reports indicate that these factions generally maintain a high level of animosity towards one another during those times that they are not actively at war.
This may be a consequence of the world's limited resources or a matter of differences in allegiance between those who follow the Ruinous Powers. Though the total number of inhabitants is unclear, as long as they remain effectively fractious, it is improbable that they could pose a meaningful threat to the galaxy at large.
These populations consistently maintain a primitive technological base. There are no known manufactoria of any significant size. Their primary armaments are mostly hand weapons constructed from stone, very limited amounts of metals, and the complex Belissaran fungal structures that serve as a wood analogue. There have been no recent reports of these mutants using firearms.
In addition to the Human populations, there are also significant incursions of Warp-spawned creatures residing upon Belissar. It is unclear how these entities maintain their existence within realspace on the world. It may simply be that the planet maintains a significant number of small rifts between the physical realm and the Immaterium.
Such tears in the fabric of reality would allow for these terrors to cross into our world at will. If this is the case, it could simply be a matter of time before something more potent exploits these tears and posing a significant threat that extends beyond this isolated world.
The Deathwatch continues to commit resources that monitor the world, so that such a threat might be identified and eliminated at the earliest possible stage.
- Deathwatch: The Outer Reach (RPG), pp. 66-69