- "The Vaults of Moravec must never be opened. You will swear this oath to me, Kelbor-Hal, or the union between Terra and Mars will be no more."
- — The Emperor of Mankind
The Vaults of Moravec were a depository of forbidden knowledge and techno-arcana located on the Mechanicum's holy world of Mars in the Segmentum Solar. Hidden in a sealed vault inside a maze of old tunnels and chambers nearly a kilometre deep beneath Olympus Mons - the mighty forge of Fabricator-General Kelbor-Hal -- the Vaults of Moravec had been deliberately kept locked by the Emperor of Mankind who correctly judged the knowledge it contained as too dangerous to be known. When Warmaster Horus Lupercal began to plot his rebellion against his father, he promised Kelbor-Hal to lift the Emperor's ban on the forbidden knowledge stored there, thus swaying this powerful figure to serve him. The opening of the Vaults of Moravec would spark the civil war inside the Adeptus Mechanicus that would become known as the Schism of Mars and mark the true birth of the Dark Mechanicus.
The tunnels beneath Olympus Mons had long served as a burial place for the adepts of the Omnissiah. Here laid a treasure of ancient knowledge, personal logs of past researchers, old dust-covered tomes of knowledge, ancient reliquaries intermittent with tombs and entire caverns harbouring the technologies developed in distant times, now nothing but heaps of rust and metal through long centuries of neglect. Hidden in the deepest and most distant corner of this maze were the Vaults of Moravec.
The Vaults of Moravec had been created especially to harbour the researches and data obtained by the ill-reputed techno-savant Moravec. Moravec had been a technical genius, way ahead of the technology of his time. He intimately believed that technology would eventually surpass human intellect and that by technological means he would be able to create this "singularity", the fusion of machine and man that would surpass both. These beliefs essentially mirrored the Mechanicum's creed that one day this fusion between man and machine, the Omnissiah, the Machine-God would reveal itself to them, which is why Moravec was also considered an important prophet of the Mechanicum. However Moravec would not be content to wait for the coming of the Omnissiah as he had heralded it, but actually tried to bring it forth. Gathering like-minded tech-adepts in what was officially branded as a sect known as the Brotherhood of Singularitarism, Moravec continued his work.
As would later be discovered, Moravec had made unholy pacts with beings far more ancient than mankind, mingling his race's science with the raw, elemental force of the Æther to create technologies far in advance of anything seen on Terra. With the influence of perhaps the Gods of Chaos or at the very least one of the more powerful Neverborn, Moravec created technical wonders; machines free of the shackles of physics and human understanding of the universe, Warp-powered devices which did the impossible and fearful -- truly devastating weapon systems that made the atomic devices of the past pale in comparison. This power naturally bred suspicion and hatred with the more secular warlords that still ruled Terra in these day. Feeling threatened, one of these warlords, the Warlord Khazar, united the Pan-Pacific tribes and stormed Moravec's citadel branding him a witch but ultimately failing to kill him. This happened well before even the Unification Wars as Khazar was himself vanquished by Narthan Dume, one of the mightiest rivals of the Emperor during His conquest of mankind’s home world. Managing to escape, Moravec fled to Mars where his story finishes. Upon his death, all his works and knowledge were interred presumably with him in the Vaults that still carry his name.
For an entire millennium the Vaults remained locked. Even when the Emperor trod the soil of Mars and visited the maze of tunnels in company of Kelbor-Hal, He didn't dare open the mighty door that closed the Vaults. Rightly suspecting that the ambitious Kelbor-Hal would not heed His Words, the Emperor psychically wiped the Fabricator-General's cartographic memory buffers, so that Kelbor-Hal would indeed know of the hidden knowledge's existence, but would never be able to find it on his own.
Two hundred years later, the Warmaster's emissary known as Regulus would lead the same Kelbor-Hal back to the Vaults and give him the means to open it. Having given himself over to Chaos, the corrupted Tech-priest mastered a corrupted version of the Mechanicum's sacred Lingua-Technis, a chaos corrupted scrap-code that infected any nearby system and succeeded in opening the inviolate door of the Vaults of Moravec. Having been affected himself and willfully entered an alliance with Horus, the Fabricator-General was infused with the scrap-code and gave himself wholly over to Chaos. With the new scrap-code embedded in his memory buffers, Kelbor-Hal would construct an army of mechanical abominations, perverted in body and in mind by the bale influence of the Warp. This was the true birth of the Dark Mechanicus as it still exists today.
- Mechanicum (Novel) by Graham McNeill, pp. 127-134