Honestly don’t expect much and I doubt it will be more than some additional vanilla. Three scoops of vanilla is nice and sweet but it’s not a lot of variety.

Besides I want to know more about the mystery.
We're supposed to get some discussion with Katie, Lily and Debbie in the aftermath of the much hyped orgy last time. While not sexy in and of itself, it should be a significant milestone in the relationship with any of those three, which I would certainly deem novel and worthwhile.
At least in theory. The fact they felt the need to add sexy bits to the discussion does not fill me with glee, but hopefully that's just a little vanilla icing on a delicious and nutritious... oat cake? I think I sprained my metaphor there, but the point is I do see potential value in the episode even if the sex doesn't pan out. So I'm going to remain cautiously optimistic.
On the mystery, I'm not expecting much. Based on everything we know, it seems like there's only two realistic possibilities: Elaine or Bella. Jolina obviously wouldn't implicate herself even if she were guilty, and she previously had the opportunity to clear Monica and (I believe) Zarah. She'd certainly recognize Theresa (or Jenna), and it would be hard to mistake any of the other girls for middle-aged.
So that leaves Elaine and Bella. Elaine would certainly give us something new to talk over with her, but we already know she's involved. Bella is my guess, because it is at least a legitimately new direction to take the story in. But it won't prove anything by itself, thus ensuring the mystery will continue for at least another episode.
That's my prediction anyway. Hopefully we'll see shortly if I need to turn in my deerstalker hat.