(At some point I need to bring this up to date, might as well start with the Tau arc).
After passing Uriel’s test of loyalty and fortitude with outstanding results, he gravely informed the Acolytes of the reason for their accelerated rise through the ranks of the Inquisition into his Inner Circle.
Whispers and rumors often surround the Inquisitor, who has not seen necessary to train or endorse any Acolytes for the better part of two decades. He has, for some time, taken care not to involve others in his operations – save for the occasional and necessary intervention of Inquisitorial Stormtroopers – preferring to use deception to pit his enemies against each other. It was therefore surprising to his superior – Lord Inquisitor Antissa Kaede – to hear that not only was he clandestinely assembling a cell of Acolytes, but also that he was so quickly divulging so much sensitive information to them in such a short amount of time. Nevertheless, she is clearly pleased with Vigilant Cell’s performance thus far, and decides to leave Uriel to his own devices for the time being.
The reason Uriel gives for his recent behavior (though even his Acolytes question if this is his true motivation) is due to the surreptitious occupation of a nearby system by a displaced Tau enclave. The filthy xenos have apparently managed to bring a handful of worlds in the Aftenbar system under their control, misleading their citizens into following their abhorrent doctrine known as the Greater Good.
The team must rendezvous with the resistance leaders on the Ice World Denel in order to begin the mission to cause the Tau incursion to implode.