Since white walkers were seen the very first scene of the show, I thought it was commonly known there would be elements of the supernatural. Like others have said, they mention that there were dragon skulls in the castle, and Ned's daughter hides inside of one. The Khalesi was carrying around dragon eggs since the beginning. Nothing concerning dragons surprised me. Now if people had come on here after reading the book and told you about someone getting killed, that would be more of a spoiler.
