The most rational choice is skipping the conflict entirely, and heading to the creche, post-haste.
Not knowing about the creche, if you find out that the True-Souls have tadpoles in their head, it's probably trying to shake priestess Gut down, which leads you killing her and discovering that the True-Souls know less than you do, which leaves you with Halsin.
At some point you'll learn about Moonrise Towers, which overrides every other choice, because you know that's the source of all the True-Souls.
