"I understand that you petitioned for a company of the Adeptus Astartes, Imperial Guard regiments, Legio Titanica and fleet support. However, your xenos problem does not require an army to solve. You need just one warrior to be in the right place at the right time."
- — Kill-marine Jakus reporting to the Syndics of Quolm
A Deathwatch Kill-marine is a specially-trained Battle-Brother of the Deathwatch who is skilled in solo operations and acts essentially as an Astartes special operator. A Kill-marine is often sent to investigate and exterminate an enemy himself where such a thing is possible or to call in backup if he determines that the situation warrants it.
Not every xenos-related threat demands the deployment of a full Deathwatch Kill-team, but many seemingly inconsequential incidents can be harbingers of a greater threat that it would be unwise to ignore. Under these circumstances, a Watch Captain will deploy these lone Kill-marines to carry out their sacred duty. Kill-marines spend time living alongside those they must ultimately defend, sharing their trials and seeing the world through their eyes.
Every xenos threat encountered by the Deathwatch does not always call for the full destructive power of an entire Kill-team. Sometimes, a mission may call for a more subtle approach, which can be handled by a lone, specially trained operative. These solo missions are the venue of the elite Astartes warriors known as Kill-marines. They are often sent in lieu of a Kill-team to investigate, and if necessary, exterminate a xenos threat or call in backup if the situation warrants it.
Kill-marines are naturally denied the reliable supporting firepower of their Battle-Brothers and fall back on the stealth and infiltration techniques they first mastered as Scout-Initiates to perform their duties. Scout Sergeants often make superlative Deathwatch Kill-marines with little additional training but these specialists are drawn from all ranks of the Deathwatch as needed.
It requires a peculiar mindset and view of the galaxy to become a successful Kill-marine. A certain independence of thought and great strength of spirit are in many ways more important than the possession of exceptional stealth skills. A Kill-marine must possess the right temperament and the mental discipline and fortitude to operate for long periods of time cut off from their kind and from the sacred touchstones of their Chapter. Yet at the same time, the Kill-marine must demonstrate a certain openness of mind and aptitude to collaborate with the non-Astartes personnel he will invariably encounter on his solo missions. Even amongst the exceptional warriors of the Deathwatch, such uniquely qualified Space Marines are few and far between.
Space Marines ordinarily live a cloistered existence in their fortress-monasteries. Their contact with the outside world is normally limited to fighting wars in it and their interactions with mortal humans only come in chance encounters on the battlefield. By contrast, a Kill-marine has to interact frequently with the existing authorities and power structures of the Imperium, often acting as a direct representative of the Deathwatch before Planetary Governors, war councils and ruling bodies of Adepts.
Kill-marines spend time living alongside those they must ultimately defend, sharing their trials and seeing the world through mortal eyes. During their missions a Kill-marine will make allies and enemies of many that they meet, and hear tales that would never reach a Watch Fortress. He might become involved in events that ultimately have little to do with the Deathwatch directly but rebound to the greater security of the Imperium. In this way the remote Deathwatch maintains a slender connection to the great masses it is charged to protect even as it stands vigil in the darkest gulfs surrounding Mankind.
In practical terms the greatest step a Kill-marine must take is to secure travel between the stars as Deathwatch vessels can rarely be spared for their direct deployment. Interstellar starships are such rare and precious things in the Imperium of the 41st Millennium that even the word of a Space Marine will not turn one from its course. More militant Battle-Brothers have sometimes opted for the expedient of capturing a pirate vessel and forcing its crew to do their will, exterminating their unwilling hosts once they reach journey's end.
However, many less drastic opportunities exist for a Kill-marine who is prepared to think more broadly. He might travel aboard Imperial Navy warships and Rogue Trader vessels for example, or join the retinue of an Inquisitor for a time if it will serve his purposes. To do this the Kill-marine may have to use his natural humility to ask, and not demand, his passage by offering his martial assistance in trade for reaching his destination.
Imperial authorities will usually welcome the opportunity to gain access to the knowledge and experience of a Space Marine for their own purposes in some vexing matter. The singular skills a Kill-marine can bring to bear are liable to open whole realms of possibility that were previously out of reach to a Rogue Trader Captain or an Inquisitor. A previously unknown and potent player entering the great game of Imperial politics can be invaluable for their schemes. The guarantees of transportation to an undisclosed location that a Kill-marine may ask for are a small price to pay to secure his help.
More cynical commentators have noted that the portrayal of the Kill-marine as some kind of diplomatic emissary is disingenuous at best and an outright lie at worst. A Kill-marine is still a Space Marine, a super-humanly fast and strong warrior trained in the very highest arts of war. Some accuse Kill-marines of being spies and assassins operating at the behest of their Watch Commander, independent and unregulated agents of a shadowy organisation with a reputation for exterminating entire worlds.
The coming of a Kill-marine may be treated with great alarm by some, an unsubtle reminder that the harbingers of death are near. Kill-marines do often forego Power Armour and use non-standard weaponry of a somewhat stealthier demeanour than the Bolter and Chainsword. They maintain that this practice is born of practicality when they are commonly moving through environments designed for an unarmoured man, and that employing more easily concealed weaponry only serves to soften their otherwise intimidating and warlike aspect. It is to be expected that such peerless warriors would adapt to their circumstances by honing their stealth and unarmed combat skills to exceptional levels so that they can slay quickly and quietly in case of trouble.
Such paranoid accusations may have some foundation in reality. At times Kill-marines have turned on those apparently giving them aid, even unto slaying entire noble households from within on the pretext of uncovering corruption in their ranks. How often these events are rooted in coincidence and spontaneous action as opposed to the carefully considered orders of the Watch Commander is impossible to say. The responses of the Deathwatch to those brave enough to level such charges are simply that those who have no truck with the alien have nothing to fear.
It is true that Kill-marines are often sent on missions obscure to their Battle-Brothers in the Deathwatch and even to themselves. The Librarium and the Apothecarion can layer mental blocks and hypno-conditioning into a Space Marine's mind to transform it into a receptacle for the most sensitive knowledge. Secret orders or communiqués that a Watch Captain will not entrust to astropathic communication may be buried deep in a Kill-marine's subconscious for him to transport to another Watch Fortress.
A Kill-marine may carry, knowingly or unknowingly, relics or other items of key importance for delivery into the hands of a specified individual. They may be assigned to guard an individual whilst at the same time having pre-programmed assassination protocols in place to eliminate them if the call arises. Some whisper that these enigmatic figures have even dealt directly with aliens, a feat that would surely require extreme Hypno-indoctrination for a Deathwatch Space Marine to achieve.
It is the life of the Kill-marine to seldom work alongside his own Battle-Brothers. Usually he works alone or in the company of powerful members of the Imperium such as Inquisitors, Rogue Traders or Tech Magos. As a result of their time away from the support of their Battle-Brothers, a Kill-marine learns to be more resourceful, develop his own combat techniques and fight as a one man Kill-team.
During his travels the Battle-Brother has come into contact with dozens of different organisations and individuals from all across the Imperium. Kill-marine Battle-Brothers are ideally suited to working alongside either Inquisitors and their retinues of Acolytes and Throne Agents or Rogue Traders and their crews. During the course of their travels it is even possible that a Kill-marine may spend extended periods in the company of such individuals and accompany them on many tasks, aiding them in whatever endeavours they might undertake. Kill-marines nevertheless always stand apart from those around them, for they are still members of the Adeptus Astartes, and will usually possess their own agendas.
Notable Deathwatch Kill-Marines
- Deathwatch Kill-Marine Semnai - A notable Kill-Marine of the Lamenters Chapter, Brother Semnai was serving his second vigil of the Long Watch at the time of the Hadex Anomaly operation, and his first spent as a Kill-marine in the Koronus Expanse. The exact nature of Brother Semnai’s service in that far distant region of the galaxy remains a mystery, and it appears he travelled on the bridges of as many as a dozen different Rogue Trader vessels. Many suspect Brother Semnai had been tasked with hunting down a specific enemy of the Deathwatch in the Koronus Expanse, and that he finally cornered that unknown foe on the very brink of the Hecaton Rifts. Other than the fact that Brother Semnai discharged his Apocryphon Oath during that final battle, all that is known is that he sought to return to his Chapter’s homeworld, his vessel laying up at Erioch during its long voyage. Needless to say, Brother Semnai never completed the journey, deciding instead to stand a second vigil after Inquisitor Ramaeus approached him and specifically requested his aid in some undisclosed task. Brother Semnai served during the Hadex Anomaly operation and the reason for his continued interment in the Erioch Reclusiam is a complete mystery.
- Deathwatch: The Emperor's Chosen (RPG), pg. 75
- Deathwatch: Rites of Battle (RPG), pp. 123-125