Game of Thrones season 6 spoilers below, of course.

Miguel Sapochnik directed the final two episodes of Game of Thrones season six, and he's been full of little details about how the show gets made. Most recently, he revealed the most challenging part of filming the season finale. In a series that deals with lots of sex, murder, and CGI to create special effects, it was a actually simple-seeming scene that proved difficult to film, thanks to certain time constraints.

Sources: The Guardian | Vanity Fair