Sunday night, HBO aired "The Last Watch" about the making of the final season of Game of Thrones. The documentary took us behind the scenes of the last cast table read where we see Kit Harrington react to a pretty big death in the finale. Going into the table read, several cast members had read the script knowing what was coming...Kit did not. You're seeing a genuine reaction here. Obviously, spoilers ahead if you haven't seen the finale yet!
You can see Kit talk about those final table reads with Seth Meyers at the 5:39 mark...