Explain how zaroff's treatment of rainsford changes during the story.

At first, Zargoff just thought this was going to be another one of his fun games, but once the game has started, he realizes that Rainsford is much smarter than anyone else he has hunted. I think Zargoff starts getting nervous himself, because hes not sure he can kill Rainsford and if he doesn't kill Rainsford, Rainsford will kill him.