7x09
I feel like this was foreshadowing that pretty much the entire cult will die at the end. Of course that's not shocking on this show, most characters are dead at the end of their seasons. But this episode really seemed to try to drive home the point that that's often the outcome for cult members.
Also, a loose end I'm wondering about, though a few episodes back. I'm wondering if they'll ever explain the gimp in the attic. Because that was just so random. Could easily be nothing, but I'm kind of waiting for a reveal of their identity as someone of more importance to the story.