wait. wait a fucking second. this whole time, everyone has been assuming that the traitor who gave away the beacons and the dynasty-side angel of irons member is the same person. but essek had nothing to do with that cult. I'm sure he would have said something in his confession otherwise, and it wouldn't make sense anyway for someone whose only concern was researching the beacons to be a cultist.
so unless the prisoner they have was in fact the cultist but not the traitor (which I doubt since he was just as confused about the cult part as he was about trading the beacons), there's still a cult member in the xhorhasian court.