I can’t figure out why the writer didn’t write just turn around when it is not in a conversational part. I’ve met a lot of apostrophes in conversations in Harry Potter books, like ’Bye and C’mon, which are used to omit some letters, which, I think, sometimes contain the speakers’ subtle emotions in it. But this is my first time to find it in a narrative part. I’d like to know if the writer is trying to achieve some effect or something.
“Look!” said Ron suddenly, pointing out of the window.
Hagrid had just straightened up and turned ’round. (Harry Potter 4 [US Version]: p.266)