Fort Obsidus
From Warhammer 40k - Lexicanum
  Fort Obsidus[1a] |
Fort Obsidus is a Watch Fortress of the Deathwatch.[1a][1b][2]
During the Fourth Tyrannic War, Inquisitor Halwyl of the Ordo Xenos requisitioned a strike force from Fort Obsidus to accompany him and Tempestus Scions from the 15th Psian Jackals regiment for a secret mission. Telling no-one but Watch Master Gharran of his objective, he led his forces to the Tyranid-infested Irontower System in the Bastior Sub-Sector before all contact with the Inquisitor was lost.[2]
