Unbelievable as it may seem, there are times when even Astartes battleplate simply does not offer sufficient protection. Most frequently, this will be in circumstances where they are required to prosecute undertakings in theatres regarded by the Codex Tactica Imperialis as Zones Mortalis. Such environs include storming breaches in fortifications, void-craft boarding actions, the clearing of bunker and tunnel complexes and the pacification of space hulks. 

In some cases, these actions may be undertaken by Breacher Squads augmented with boarding or breacher shields, but in circumstances where the probability of survival is rated particularly low and protection is therefore of utmost concern, Tactical Dreadnaught Armour is likely to prove the best option.

A product of the Terminator programme which sought to create the ultimate protective armour for the Legiones Astartes, Tactical Dreadnaught Armour harnesses the capabilities of civilian exo-environment suits that are able to withstand such lethal environs as those found within the containment fields of macro-plasma reactors by combining ceramite and plasteel plating with adamantium bracing. 

According to Kordhial's Liber Armorum Imperialium, several patterns of Tactical Dreadnaught plate were developed by competing armourers, including Kataphraktii, Tartarus, Indominus and Saturnyne with each variant possessing uniquely defining characteristics and appearance but ultimately offering roughly analogous levels of protection to the wearer. 

Such protection came at a price though and an Astartes must undergo extensive training before being certified to fight wearing a Tactical Dreadnaught Armour as the bulk and reduced agility of the suit can wrong foot the inexperienced and render even the most decorated of veterans vulnerable to more numerous or more lightly armoured foes.

But to master Tactical Dreadnaught Armour is to be able to walk unscathed through storms of shot and shell that would prove the death of a lesser armoured warrior.   

Illiatariu. C., Rememberancier Documantist Minoris. To Walk Among Demigods. A Treatise Upon The Nature of The Argyntum Stellae., Published 863.M33, Sector Heliopolis, Segmentum Pacificus. 

I will be the first to admit that I have little by way of a frame of reference since I have spent precious little time around anyone with psychic abilities before, but being in the presence of a Quæsitor is an unsettling experience to say the least. Indeed, one could write much upon the subject of mankind's abject fear of and utter reliance upon the psychic members of our species, but I shall refrain from such digression here.

I am given to understand that the majority of orthodox Astartes chapters maintain a Librarius. There are of course exceptions to this, perhaps the most notable being the Templarum Ater, who I am assured reserve nothing but hatred towards those with even the barest hint of psychic talents. Within those chapters possessed of them though, in addition to such mundane tasks as record keeping and counselling their war leaders, the Librarius maintains oversight of the wellbeing and training of the battle-witches of the Adeptus Astartes. 

While the intricacies of the rituals and teachings that are their stock in trade are far beyond my comprehension, I believe that the origins of the Librarius lie within the Magna Crucis, though it was censured and disbanded by the Master of Mankind before it took root in all of the Legiones and was ultimately only resurrected in desperation as conventional warriors found they were all but powerless to combat the warpcraft wielded by those gathered to the banner of The Serpent. 

I believe that much of the garb of the Librarius emerged in this tumultuous time as well.  Indeed, Æplogestes's Admonitio Historiæ Imperialis suggests that the distinctive Psionic Hoods worn by members of the Librarius were derived in part from technoarcana recovered from the ruins of pre-Imperial cultures by the Mundi Comedentii and Manus Ferreae which took the form of collars of blackened silicate that, at great cost would allow the wearer to quiet the Immaterium, though I have been unable to fully corroborate this assertion.

If [REDACTED] is to believed, and I find I have no reason to doubt the veracity of his statements, then while they may appear similar in function and form to their Imperial counterparts, the origins of the abilities and armaments of the Quæsitors lie far earlier in the history of mankind, being instead derived from lessons hard won by a handful of Astartes with latent psionic abilities out among the Halo Stars. I believe that the Astartes do not feel fear, but what horrors must they have endured alone the darkness while attempting to gain understanding and mastery of their abilities? 

As comfortable as I was to eventually become among the majority the subjects of my rememberance, I remained unable to be entirely at ease with [REDACTED]. Merely being in his presence was unnerving enough as I have said, but when he revealed to me the power that Quæsitors possess in the disciplines such as divination, telepathy, fulmination and geomancy, a fear I could never entirely quiet remained ever present in my thoughts. To earn the ire of an Astartes would be terrible enough, but to anger one possessed of the ability to conjure fire from thin air, shatter the very earth itself or still hearts with but a thought would be so very much worse...

Illiatariu. C., Rememberancier Documantist Minoris. To Walk Among Demigods. A Treatise Upon The Nature of The Argyntum Stellae., Published 863.M33, Sector Heliopolis, Segmentum Pacificus. 

Spear of Volnoscere. Bastards of Siklon. Reavers of the Void. It could be said that the Inanis Barones accumulated titles like they appropriated vessels but while names are easily afforded, not all are as deserved as they may seem.

That the Barones were masters of boarding actions and shock assaults is without question. Similarly beyond doubt is that they, like many before them, ascribed to the the belief that ‘might makes right’ which was to bring them to blows with those with whom they had common cause on more than one occasion.

But a more than momentary glance into the light cast by the names they were given though would reveal a more complex picture of misunderstanding and misrepresentation. Ever has truth been among the first casualties in the conflicts of man. 

Despite my misgivings, for the reputation of the Barones preceded their arrival, I found that [REDACTED] was unusually amiable for an Astartes, though at times I found his humours leaned more towards the melancholic and he was given to a sentimentality that in my, admittedly limited experience was rarely found in trans-humans.

The Sorrowful Years would come to visit much sadness upon Sectors Heliopolis and Morqub, but I felt an unusually personally loss when I learned of [REDACTED]’s death at the hands of Ordo Astartes agents and I shall always regret that I was unable to spend more time in his company as we would often discuss matters beyond those warcraft and battle tactics...

Illiatariu. C., Rememberancier Documantist Minoris. To Walk Among Demigods. A Treatise Upon The Nature of The Argyntum Stellae., Published 863.M33, Sector Heliopolis, Segmentum Pacificus.