These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Moral Event Horizon: When Zachary helps the People Across the Lake kidnap Polly, and is (initially) willing to use her as a sacrifice. This is one in-universe (to Polly) as well, as, once everything is settled, Polly makes it clear that their friendship is over.