Lewis Gribben, Siena Kelly and Emma Corrin in Black Mirror season sevenThis article contains spoilers for the latest season of Black Mirror.Black Mirror is back – and its new dystopian stories have already won over critics and generated a lot of conversation.In the lead-up to the return of the award-winning Netflix anthology series, HuffPost UK spent some time with the cast and the crew to find out exactly what goes into making an episode of Black Mirror, and they shared some stories that fans will no doubt find very interesting.Here are 17 behind-the-scenes secrets the stars of Black Mirror shared with us about the show’s seventh season...For starters, creator Charlie Brooker opened up about why USS Callister became the first Black Mirror episode to get a sequelAccording to the Emmy winner, there were “two reasons” that season four’s USS Callister got this distinction.Charlie explained