As far back as Rourke can remember he has dreamed of standing at the left hand of the God-Emperor. The path that led to his becoming an Arbitrator was, in his own mind, pre-defined. A child playing where he shouldn’t be… a member of a nobel family meeting with an ambassador of an alien race in a secluded location. What he saw sparked a life long obsession to find the evidence needed to bring down a family who’s head is the governor of his hive world; the emperors world.
He joined the Adeptus Arbites as soon as he was able and served as hive population control during the day and detective with every single spare hour he could find. He pursued his goal with unatural zeal. He was commended many times and refused promotion from trooper at every opportunity; knowing that the governing family would watch the progress of everyone on lower and mid levels. He used his anonymity to forge a network of contacts, fashion disguises and employ all out skullduggery to achieve his goal.
Over 30 years later, achieve it he did. His own family had gone during that time, he had heard they where brutaly murdered by a hive scummer gang, he was away at the time, mascerading as a sanitation operative for a mid level family who worked in adminitration. He was angry that the local police forces hadn’t protected his familys district better, but this kind of petty crime happended all the time. His family would forgive him because the Emperor would forgive him.
Using a Psyker to transmit his lifes work of collected data towards the nearest known location of Imperial Inquisition he then employed his network of contacts for the last itme to find a path to the upper levels where he passed judgement on all of the heretics.
So here he was, following the man Drellic to what he felt was another stepping stone in his pre-defined path of total servitude in the service of his God-Emperor. Inquisitor Hassen had requested his pressence, which had came as no suprise; It is hard to pass under the radar when you execute a govenor of a hive world for herecy.