Um, can someone kindly explain the ending? I don’t get it 
There’s a book about our beloved cemetarian? 
I mean, I know people who could write a book about her, but just didn’t know it had been done.
The ending is kind of complicated. According to Hilde’s father, the book ended with the party, and he and Hilde are discussing what was left out of the book (current astronomy, how we all are made of stars, etc.). But what he does not know is that Sophie and the philospher actually escaped from the book, and now live in an alternate fantasy world. Sophie went to visit Hilde, and see who she was.
Hilde is convinced that Sophie escaped the book world. Her dad is trying to tell her that is not so. Sophie knows that she cannot interact with people of the “real” world, but she wants her presence to be known, so she grabs a hammer that was on her fantasy convertible, and goes to bash Hilde and see if there’s a reaction.
When she does that, Hilde does feel something, but her father says it is only a bug and they go inside.
Do you have more specific questions? I think what was meant was for us to contemplate the posibility of an alternate reality…