The Nocturnum is the Spectra's secret service, an unacknowledged order that works exclusively in the shadows to protect the Imperia through espionage, assassination, and covert operations. Their existence is officially denied.
The People: The Umbratrix
An Individual: An Umbrator
The Leader: The Umbrarch (The Grand Spymaster)
Nocturnus: A cell leader or a master of a specific discipline within the Nocturnum (e.g., Nocturnus of Infiltration, Nocturnus of Interrogation).