I suspect some of you may say this is where I'm stretching this theory. But Marcia is where I think the theory is the strongest. Or, at least, she's what made me want to explore the theory more.
Marcia represents Israel. She has Logan's ear in a way that none of the kids have it, and they're suspicious of her influence.
Even more interesting, I think the show hints at the possibility that Marcia might've been an Israeli spy...
