Had horrid misgivings as to whether the reasons for Christine's reaction after the song are actually going to be clear here, given that — because of the structure of the story (quite apart from the symmetry of the Raoul/Christine/Raoul layout, Christine doesn't get any more 'off-stage' moments in the musical!) — we don't actually get to see her point of view at that juncture, or indeed see anything of what goes on after Raoul leaves the scene...
So I made a couple of little changes to this chapter and possibly the next, in the hopes of making that part of the story's plot a bit clearer. I'd appreciate knowing whether this comes across as a plausible interpretation of what we see on stage... which I always did feel needed a bit of explaining. It's just that I'm not at all sure the theory that I've used here is actually apparent.