These are my memories of Secret's Hold, pulled together for general reference at Dosdamt's request...I figured this was a better option than an info dump in the middle of Welcome to the Truth. Some of the memories may be horribly inaccurate, but there you go.
Inquisitorial Activity at Secret’s HoldPre-Conclave Era
Secret’s Hold was discovered by a young Inquisitor Balkoth some time in the sixth century of M41. The underground complex was clearly of alien construction, and he came to believe that its original purpose had been the scientific study of Chaos, which was his already own driving passion. Whatever he attempted there had enough success that he made it his base of operations for the rest of his career. He never reported his discovery to the Ordo Xenos or any other Imperial body, going to great pains to ensure that the jungle planet he found it on was recorded as a Deathworld of no particular value and left well alone.
Balkoth finally abandoned Secret’s Hold after being excommunicated in absentia for daemonic corruption (a fair cop), but its existence remained a closely guarded secret and was never discovered by his enemies. It passed then to Inquisitor Mentirius, a former acolyte who had spent time in the Hold while training under Balkoth – a period which also saw the betrayal of Inquisitor de Valdi, discussed elsewhere. Having returned seeking the truth of his mentor’s alleged corruption, Mentirius found Secret’s Hold empty, transferred his own operations there and continued the research. It remained a private retreat and laboratory for him until late in the tenth century, with the advent of the Nexus Schism, when he opened its doors to the Dessemusian cell* as a refuge from Puritan retribution.Conclave Era
There were two battles for Secret’s Hold, both involving Charax the Eternal. The first took place while the Dessemusians were holed up there, following the rescue of a freshly excommunicated Alessandro Nexus from an Inquisitorial prison ship. Charax turned up at the Hold to claim Alessandro, whom he had already made a bargain with, while Mentirius tried to deny the daemon prince entry, fearing for his friend’s soul. Charax flexed his psychic muscles, Mentirius realised he was outmatched and backed down, Nexus went willingly and the Hold remained mostly intact, though the outer labyrinth was reduced to dust. Disheartened by this turn of events the Dessemusians dispersed, Mentirius included; taking most of the Hold’s contents to his field headquarters, the vessel Black Silence.
At some point during the next decade the site was used for a one-off Carnage tournament (meaning shots of the Hold and the surrounding jungle would actually have been televised on at least one Imperial planet, albeit as “a secret location”) and soon after was taken over by the other Inquisitor Nexus [username: station] who was also a Xanthite and a close ally of Mentirius, although rather more moderate and generally seen as less insane than his namesake. Contrary to occasional historical confusion, the two Nexuses were neither the same person nor related to one another, save by coincidence.
The second and by far the more destructive battle for Secret’s Hold was fought while Mentirius journeyed in the webway with Alundirel, having left his lieutenant Dawn Oculis (a.k.a Rivara) in command of Black Silence.
As his absence wore on she became increasingly worried by the rise of the daemon Amon Dull, which she and her employer had recently encountered and had implied a connection between the radical Inquisitor and itself. Dawn sailed the vessel back to Secret’s Hold to consult with Nexus, knowing from Mentirius that he could be trusted. She then made the mistake of descending into the planet’s atmosphere (although warp capable, Black Silence was a relatively small vessel, built for speed and stealth). Within hours of her disembarking to the Hold, the ship was attacked by a band of Dark Eldar raiders – pawns of a Slaaneshi daemon affiliated with Amon Dull, in a complicated plotline I shan’t go into here. It is likely that she was also being manipulated down this course; in her case by a daemon sword she had appropriated from Mentirius’s vault in his absence and lacked the mental discipline to control.
In the ensuing conflict, Black Silence
was shot down, crashed into the jungle and burned, starting a fire that spread rapidly through the jungle. It is worth noting that at this point, the ship contained all the hard evidence that existed of Mentirius’s Xanthism (which he publically and privately recanted after hearing news of the atrocity on Leon San V, though he never got around to destroying many of the dubious artefacts he’d collected in his younger days). Dawn and Nexus sallied out with their respective retinues to defend Secret’s Hold, fought their way to the wreckage of the ship and managed to kill the Dracon leading the raiders. Most of the retinue members died in the process, and Dawn was mortally wounded.
All this action finally awakened the true master of Secret’s Hold, a Keeper of Secrets whose essence dwelled in the heart of the planet. It manifested on a titanic scale, tearing open the Hold from the inside as it burst out of the depths. It took a step, crushing trees flat with its hoof, and was immediately attacked by Charax, who had been covertly keeping an eye on the planet since his last visit. Following a brief, violent battle, the Eternal flew down the Keeper’s throat and ate it from the inside, halting the planet’s transformation into a Slaaneshi daemonworld and leaving himself exceedingly full (power that came in handy when he fought one of the Amon Dull fragments soon after). He didn’t put out the fire or pay much attention to Inquisitor Nexus, but he did pause long enough to heal Dawn’s injury with a dollop of Nurglish slime, later claiming her as one of his servants – which angered Nexus and Mentirius no end, though in the long run there was little they could do about it. The action moved elsewhere and Secret’s Hold was left to moulder. Centuries passed and here we are. *Dessemusians:
Associates of Dessemus, an Inquisitor who ended his career with a public declaration that he believed the High Lords of Terra to be heretics who intentionally perverted the Emperor’s Word. He was captured by Puritans during the rescue of Alessandro Nexus and summarily executed. The cell of radical Inquisitors who had masterminded the rescue named him a martyr and came to be known as Dessemusians by the rest of the Inquisition, though not all of them agreed with his extreme views. In the long run, the eventual recapture and execution of Alessandro Nexus overshadowed the memory of Dessemus, to the point that while his name is still known by History, even the Inquisition has largely forgotten the man himself.
See also Dessemus II / Novus Versaal, a cult leader who renounced Chaos after the Battle for Aithol, becoming a herald of the entity known as the White Child. He changed his name in tribute to the first Dessemus, whose death was still a recent event in his lifetime, though exactly why he chose to do that is lost to this scribe’s memory.
Secret’s Hold was built of a smooth, impermeable black material usually referred to as stone, though it is possible that its origins were synthetic or organic. It resisted scanning and erosion with equal effectiveness, though not infinitely so – as demonstrated when accelerated ageing destroyed part of the labyrinth, though how many subjective years it took to crumble is unknown. Beneath the accessible part of the Hold, long spikes of the alien material extended deeper into the planet’s crust.
There were two entrances, both concealed by vegetation. One was large enough to admit vehicles and descended into the earth via a series of ramps, while the other had to be entered on foot and in single file, consisting of a spiral staircase that wound down a straight shaft. Both tunnels culminated underneath the Hold proper in a manner similar to the set-up of a Beaver’s lodge. Having descended, a visitor had to find their way up and into Secret’s Hold through a pitch-dark labyrinth loaded with built-in traps; further imperilled by genetically engineered monstrosities set loose down there by Inquisitor Balkoth (their number added to, it must be admitted, by Mentirius). There must however have existed a clear path through this labyrinth for any were lucky enough to find it, or who knew the way already. The width of the primary entrance tunnel allowed for vehicles to be stored there, but unloading anything fragile from one would have required certain knowledge of a safe way through.
The architecture inside lacked hard edges or ornamentation. Otherwise straight walls bowed inwards when they meet floor or ceiling. A grid of shallow grooves mimicking tiles divided the floors, though on closer inspection there were no visible joins. The ceiling was slightly concave, studded with round, shallow domes of crystal set at regular intervals, that glowed in response to proximity and could be switched on or off at will by a trained psyker. Whether psychic energy actually powered the lights or merely triggered them was unclear, but they all worked without fail until the Hold finally erupted, at which point they went permanently dark.
Whatever the various rooms had been built for, most of the smaller ones were ultimately used as storage, for everything from basic necessities to hazardous materials and scientific instruments. Others would have acted as cells, housing specimens or experimental subjects; larger chambers were used as laboratories, with a relatively small section given over to living quarters for the researchers and their families. Its maximum capacity would not have been more than a few hundred, for while its layout was extensive, the corridors were narrow and the majority of its chambers lacked enough space for any significant gathering. At its heart was a tiny room with a high ceiling housing what appeared to be an altar, and was certainly used as one on occasion, but the Keeper of Secrets smashed directly through the middle of the Hold as it manifested, so this was almost certainly destroyed.