The current generation of servants in Watch Fortress Erioch's Tower of Brass, the Inquisitorial headquarters for the watch fortress, are mainly descended from his prisoners, trapped in bureaucratic limbo once they were exonerated by evidence uncovered after his death.
A trail of lost artefacts and botched missions followed his retinue that was so dismal and persistent that some suspected a cunningly-hidden secret agenda was being played out.
If so, it was being done beneath the very noses of the Ordo Xenos and surely with the collusion of many of their most highly-placed members. The majority of Barnabas' contributions to the ordo's knowledge are now sealed away inside quarantine zones in the catacombs, allegedly too dangerous and toxic to approach.
Barnabas was always fond of bold gestures and cut an impressive figure to the masses, very much fulfilling the commonest conceptions of what an Inquisitor should be.
His sweeping pogroms were always a terror among the nobility, and that gave him a good deal of popularity with the workers. Unfortunately, Barnabas' cloak and impressive armour failed to impress the Aeldari in a skirmish on Andronicus and he met his demise there on the end of an Aeldari Fire Lance.
In recent years, however, evidence came to light that Inquisitor Barnabas was under some kind of alien influence, at least during the latter parts of his career. The Deathwatch intends to retrace Barnabas' movements so they can track down where he was turned, how, and -- most importantly of all -- who knew of it.
Unfortunately, the reports, logs and journal entries they will need to analyze are sealed off in highly dangerous quarantine zones deep in the watch fortress' catacombs.
Perhaps on a related note, something Barnabas left in the catacombs is threatening to create a new quarantine zone. The source of the threat might be an alien artefact building to overload, a swarm of hungry hatchlings, a deadly viral plague or even a temporary Warp Gate. Whatever the truth, it needs containment.
- Deathwatch: Rites of Battle (RPG), pg. 238