His world - or universe or reality or whatever it might be - sounds so remarkably bizarre to Hermione, and Mac can probably see the inquisitive hunger in her eyes as she tries to take in his every word and process it and try to make it make orderly sense in her mind. It isn't working out so well, honestly. To her credit, though, it's quite a lot to take in.

"So... you have a little robot companion known as a Ghost?" she asks, trying not to sound too bewildered. "And it's sort of like a ghost of your own... soul? So is it a physical being, or more of a metaphysical one?"

Magic is magic, but the metaphysical implies something else entirely, something with which Hermione is not at all familiar and would have no idea how to even begin to rationalize within her current worldview.