@WritingMutt "Slight case of severe writer's block." Great way to put it. Um, I would suggest that you take a couple of hours just to brainstorm. Of course, you've probably already tried that, so I might be able to help you there. At the end of the last chapter, Jikida said that Mr. Griswold needed to meet someone. Honestly, only you know who this person is actually supposed to be, because there are a lot of different people this could be. You could introduce us to a high figure in the book. A position of power, like a king or something. Maybe on the way you could introduce us to the antagonist or a minor role of the book. Or maybe you could be taking us to meet someone like a teacher or something since Mr. Griswold here is just getting started in magic. You could take us to meet a professor or someone who knows about the "X-matter" stuff that you mentioned. There are so many possible aspects of the book that you could introduce in this moment. You have just plunged your readers into a whole new world that they know almost nothing about. Take this time to introduce us to this place and just have fun with it. Anyways, sorry if this didn't help, but I tried my best, so hopefully it will...
(Note: I realize I never actually said, but every time I used the word "us" I was referring to your readers)