Yussa considers that, mind turning over the possibilities and he nods. Caleb is right - there is some rhyme or reason to this, even if it is not immediately obvious. Gods, every inch of this place they explore gives him more cause to dislike Halas Lutagran. It also gives him more cause to admire him, which is worse.

"Then we start moving inward," he says after a moment, considering their options. "... And I think we ought follow the stream. The breeze has no direction, but that does."

It's as good a place to start as any, isn't it? And it provides a steady landmark to follow inward - it's path seems relatively straight, all told.