Battle of Helsreach - Oberon: Grimaldus had learned that one of the stations manned by the Armageddon Steel Legion in the wastelands surrounding Helsreach was a sealed Adeptus Mechanicus facility. The Guardsmen were only positioned around the facility and had no access to its interior, as it was considered to be sovereign Mechanicus territory.Grimaldus was told that a deactivated relic from the First War for Armageddon was stored therein, but the exact nature of the device was kept secret by the tech-priests of Mars, and not even Armageddon's High Command had any knowledge of it.Grimaldus, like all of the Black Templars sent to Armageddon, had been schooled in the history of the world and its past battles, and possessed knowledge similar to the Armageddon Steel Legion officers.Unlike his Human allies, however, Grimaldus believed that the device impounded by the Adeptus Mechanicus was a powerful weapon, first constructed and deployed on Armageddon six standard centuries prior -- the Ordinatus Armageddon.Grimaldus had not cared for what caused the Adeptus Mechanicus to hibernate the weapon and, more importantly, to not deploy it to the world's defence. His only concern was winning the war and he believed that with this artefact Helsreach might stand a chance against the Greenskin onslaught.To this end, Grimaldus, alongside the Master of the Forge Jurisian and Adjutant Quintus Cyria Tyro -- Armageddon High Command liaison to Helsreach who was brought along to deal with the Astra Militarum personnel around the instalation -- boarded one of the Black Templar Thunderhawks and made their way to the station, leaving the knights of Dorn in Helsreach under the command of the Emperor's Champion, Bayard.The three of them descended into the vast subterranean complex which stretched several kilometres downwards and seemed to be completely vacant, with not a single guardian left to protect the facility. The Black Templars and the Human accompanying them went forward, stopping only at massive doorways blocking their path, and allowing Jurisian to work on opening them.Each of these gateways was four metres thick and it would be implausible to try to open them with force, especially since, as Jurisian noticed, such an action would be likely to activate the dungeon's manifold defensive mechanisms -- this being the reason why no biological or augmentic guards were required.The Master of the Forge succeeded in cracking the code safeguarding each consecutive barrier and forcing them to open, taking more and more time on each occassion as the code's sophistication grew progressively more complex the closer to the facility's heart they were placed.The penultimate barrier was opened a full nine solar hours after they had entered the facility, but then their efforts were rewarded. On the final doorway, inscribed in letters as high as a Black Templar was a single word -- Oberon -- the name of the hallowed Ordinatus Armageddon.This discovery, however, was of little immediate use, as the inner vault in which Oberon had lain slumbering was designed and built to withstand a direct orbital bombardment and to even endure the world being condemned to an Exterminatus, while the door was sealed with at least a billion individual codes.Jurisiad had declared that it would take him no less than nine solar days to overcome this safeguard, and requested for his servitors to be sent to him to assist in the task.Unable to help the Techmarine in any other way, Grimaldus and Tyro returned to the surface, and on their way back to the hive city they had received the news of Ghazghkull's most recent move -- true to Yarrick's predictions, the Ork had ordered Hades Hive to be obliterated from orbit.