I am currently running my group through Purge the Unclean, starting with Rejoice for you are true (RFYAT).
Previously the group had succesfully completed Illumination so they were fully up to speed on Aristarchus' downfall and the use of the Emperor's Tarot.
Now RFYAT start off with the discovery that the Joyous choir are using the same tech in their Harmony Meters to guage the suitability of victims of psychic potential so they can be turned into Farcosia.
Now my understanding is that as well as helping Laurent Strophes find out what happened to his niece the over arching goal is that Varak wants the group to find out who got to Aristarchus and why. It all starts off well with the plot hook mentioned above but from my reading the climax and conclusion does not touch on the Illumination/Aristachus bit at all.
The group basically find out that it is a big drug scam run by a shadow group known as the Serrated Query and somehow they have got hold of tech from the Adraanti civilization. Where is the link to Aristarchus?
Sorry if i have missed something stupidly blatant, wouldn't be the first time, but just wanted confirmation of the above so I can think of something suitability dark and mysterious to link the Serrated Query to Aristarchus.