During the mission to Eleusis, the team discovers that an unidentified Inquisitor has been destroying evidence. Their investigation suggests that they could learn much more from another Inquisitor, Tellemain, located on Alphos. But, when they arrive at that world, they learn from her Interrogator, Darius, that she has gone missing, just before Darius is assassinated.
Further search reveals that Tellemain was apparently taken by Black Templar marines to the oceanside community of Imperiopolis. The team proceeds to the port, learning that a group known as the Brotherhood of the Perfected Truth has been operating in the area from a hidden base. Determining that they were somehow involved in Tellemain’s kidnapping, they locate and assault the base. Inside, they find Tellemain, held prisoner by the same Emperor’s Children marine captain they fought on Cressid. They defeat the Alpha Legion marines that he was using to kidnap her before he again escapes through a Warp Portal opened by a Chaos Marine Sorcerer with him.