And this is when my poor, dear Arthur finally ends up losing his humanity. No, it doesn't happen right away. In fact, he goes through quite a bit of struggle before he's forced to use the Keys or else lose the House to Nothing then and there. I almost cried when he realized he was no longer human, but I have to applaud him for managing to find a silver lining to it all.
In all, probably one of my lesser favorites of the series simply because 1)Arthur is a bit grouchy due to the fact that he's nearly lost his humanity and 2) while plenty does actually transpire, it feels like not too much important happens.