The Order of Silence/Halcyon -Allied or synonymous with the Ordo Historica Veritas -Members first encountered in the  Quarantine Zone ; cultists of higher rank seem to be equipped with Asterii Devices (thus far we have observed skilled wielders of a Communior , Augmentor , and Voiddelver ). -Members encountered thus far have physically appeared no different to hivers, and no uniform or identifiable symbol of membership has been seen. -The purpose of these members has been deliberately obscured by those who we've spoken to; some part of their mission seems to involve Ambassador Lethe , at the very least, remaining ignorant of the details of their cause. To do otherwise would be to "break the silence" that they are dedicated to keeping. At this point, it appears likely that their mission relates directly to the secret histories of the planet. -The mantra repeated by their members is: "The Emperor Protects; Silence is Halcyon." Though this indicates they follow the Imperial Creed, it remains possible that their methodologies are heretical, considering their strange behaviors and clear willingness to engage in hostility with our forces. -The aforementioned attack occurred almost immediately after Specialist Ford translocated out of their range of vision, into a hidden chamber of their base. This prompted immediate mistrust and violence. -The hollow space underneath the chapel was observed by Ford to be of Asterii design, constructed of the familiar, obsidian like material seen in others of their locations. A Voiddelver portal was also present (later used to exist the Zone). There was also an odd collection of carapace armor, weapons (modified las pistols), and a dataslate containing encoded information: TRANSMISSION - HALCYON SECURE CHANNEL FROM: Sevenstar TO: Agent Mourningtide Priority Alpha Security Level: Obsidian Target Document: "Supply Manifests of the Jericho Exchange" Current Location: Secondary Archives, Hive Asterion Level 442 Document Status: Uncovered by Junior Archivist Pellus Denn during routine reorganization. Archivist Denn has filed a request for document authentication, citing "anomalous trade patterns" and "inconsistencies with established historical record." Request is currently pending review by senior staff. Timeline of review unknown, act quickly. OBJECTIVES: Secure and destroy target document before authentication process begins Ensure no copies have been made If Archivist Denn has examined contents in detail, assess contamination level Apply standard containment protocols as situation warrants, cleansing is authorized PARAMETERS: Maintain Halcyon deniability Stage incident consistent with standard archival accidents Avoid casualties unless contamination confirmed and cleansing infeasible Document must not reach Senior Archival staff The Emperor Protects, The Silence is Halcyon //END TRANSMISSION// -The record they sought to destroy can be found here .   -Halcyon appears to be backing Harkan Jharn in his attempts to lead the Regulars into war with the Eternalites (though Jharn himself appears to be unaware of their presence or true nature). Their reasons for doing so are unclear at this time. It is possible that they made contact with Jharn during his pilgrimage to Vallis Decimae .