"Hmm. I'd've guessed he was at the very heart of it, surrounded by as much protection he could manage, though I suspect you're right. In that case..." She points to one of the towers, angling downwards at a sharp angle, longer than any of the others. "If you're right, he's probably in there. Which means..." she gestures, using an illusion to draw an arrow to the tower opposite the one she'd indicated. "The entrance would be there."