As told by Ploon Kloovs:
Apparently, the Illithid teleported us to the moon, Selune. All manner of odd creatures and strange equipment was there, and we determined that we should claim it all for our own use. I allowed myself to be captured, and discovered that was also already a prisoner there, evidently being replaced by more dopplegangers, of a sort. We freed him and continued to claim the Selune base.