[ It's a risk but he has to have a chance here. When he sees the ten, he huffs and looks off angrily for a moment. ] Whatever. Let me deal next time, alright?

[ Luke must be messing with him. But he's also thinking about how to explain the trees because he'd intentionally avoided talking about Cabeswater. It might narrow its location down too much and he can't tell anyone about where it is. ]

I don't know. It's worded strangely. I think it comes from the fact that sometimes trees house the magical properties of the leylines. They manifest it. So ultimately, magical trees.