Billy trying to get Harry out of his Grave Peril induced funk at the start of the story.
Harry and Murphy have an especially sweet and close relationship here, with what she went through in the previous book making her more vulnerable, and Harry swearing that he won't let anything like it happen again.
Also, Murphy letting Harry put a defensive charm on her. Not that she has any reason to doubt him, but she's so scarred from her previous experiences that seeing an approaching spell is almost enough to break her. One would expect her to be too shaken to allow any spell on her, but she lets Harry do it without any exitation. It speaks volumes about how much she trusts him.
Fix attacking Lloyd Slate, the Winter Knight, who had terrorized him and his friends for years, just because he hurt Meryl.