Purpose.

HUGO: Monsieur Labisse gave me a book the other night.  He's always doing that, sending books to a good home.  That's what he calls it.

He's got real ... purpose.

ISABELLE: What do you mean?

HUGO: Everything has a purpose, even machines.  Clocks tell the time and trains take you places.  They do what they're meant to do.  Like Monsieur Labisse.

Maybe that's why  broken machines make me so sad.  They can't do what they're meant to do.  Maybe it's the same with people.  If you lose your purpose, it's like you're broken.

ISABELLE: Like Papa Georges. 

HUGO: Maybe we can fix him.

ISABELLE:  Is that your purpose, fixing things?

HUGO:  I don't know.  It's what my father did. 

ISABELLE:  I wonder what my purpose is. 

HUGO:  I don't know. 

ISABELLE

Maybe if I had known my parents ... I would know.

HUGO

Come with me.

Right after my father died, I would come up here a lot.  I'd imagine the whole world was one big machine.  Machines never come with any extra parts, you know.  They always come with the exact amount they need.  So I figured if the entire world was one big machine ... I couldn't be an extra part.  I had to be here for some reason.

From the movie adaptation of Brian Selznick's novel, The Invention of Hugo Cabret