Okay, so Shank says he's not the one carving the musical symbols into the corpses and I had always wondered why he would do that. He didn't strike me like the type. And now he has confirmed that.
But with the mention of the witch who I assume is Irene Mend who is now presumably in Diggory's body, I can't help but think back to that one theory I saw early on in the season (I don't know who said it) that maybe it's Percy who carves the symbols into people? But why?
Omg, I just had a thought! What if Percy is body hopping and trying to find a way to tether himself somehow? What if Irene/Diggory is helping him? 👀










