As far as we could tell they actually wanted to wait for a bit longer. Jon sort of stumbled onto their hiding spot by mistake. Found a fake wall in the archives and when they poked their heads through it; worms. Killer worms everywhere.

Yes; I believed they worked as a hive mind for as close as I ended up getting and I wouldn't want to repeat any of that day to confirm that. And I don't think they were exactly doing Elias's bidding. From what Jon told me is that Elias needed him marked by all the fears to complete a ritual that he wanted to do. Although, considering we nearly died? I don't think that was the full plan.