Harry Potter and the goblet of fire, the movie. I have a question?

In the movie, after the scene where Dumbledore speaks about what the
goblet of fire is and what the students have to do in order to enter
the Triwizard Tournament, there is a scene in which you can see
Karkaroff getting suspiciously into the great hall. What is he doing?
He's not the person who put Harry Potter's name into the goblet, so I
was wondering what that scene means.
Thank you!