Lord Arkona is in an all-hands meeting with the other Arkonas in the Vault, because it's high time to get everyone on the same page.
Back in the mansion, he turned on his mindreading as a poor man's see invisibility, and wound up reading the minds of those fucking guys - you know the four (although only three of them actually failed their saving throws). They are incredibly weird and not to be underestimated. They share a supernatural ability, although the specifics of how it works are unknown to him and explaining what he does know is - going to take some explaining.
First of all, all three of them were pretending that they had been pretending that their actions were determined by an outside power, but that they'd recently decided to pretend to have deduced that this was, instead of being their imaginations, the case.