Does “One” here refer to “someone in our world” or does it refer to anybody in general?
“So it was the horn—your own horn, Su—that dragged us all off that seat on the platform yesterday morning! I can hardly believe it, yet it all fits in.”
“I don’t know why you shouldn’t believe it,” said Lucy, “if you believe in magic at all. Aren’t there lots of stories about magic forcing people out of one place—out of one world—into another? I mean, when a magician in The Arabian Nights calls up a Jinn, it has to come. We had to come, just like that.”
“Yes,” said Peter, “I suppose what makes it feel so strange is that in the stories it’s always someone in our world who does the calling. One doesn’t really think about where the Jinn’s coming from.”
I don’t know why you wouldn’t believe it," Lucy said, “if you believe in magic at all. Aren’t there lots of stories where magic forces people from one place - from one world - to another? I mean, in the Arabian Nights, if a wizard summons a djinni, he has to come. We had to come, just like that.”
“Yes,” Peter said, “I suppose that’s why it feels so strange, because in the stories it’s always someone from our world who makes the call. You don’t really think about where the djinn comes from.”
‘one’ refers to any person, but not a particular person. However, nowadays, ‘one’ is very often replaced by ‘you’ also meaning the same as I’ve explained above. I think that ‘one’ is used to be formal.
The pronoun ‘we’ is also used in the same sense as ‘you’. In my view, the use of ‘we’ becomes more inclusive and less condescending while making such general or distributive references.
