Certainly no one believes the dragons that have thrilled viewers of HBO’s hit series exist in any real sense. And yet it’s still somewhat surprising to see the British actor Emilia Clarke, who plays exiled queen Daenerys, straddling the “buck” on a soundstage at Titanic Studios, a film complex named after this city’s other famously massive export.

The machine under Clarke looks like a big pommel horse and moves in sync with a computer animation of what will become a dragon. Clarke doesn’t talk much between takes. Over and over, a wind gun blasts her with just enough force to make me worry about the integrity of her ash blond wig. (Its particular color is the result of 2½ months’ worth of testing and seven prototypes, according to the show’s hair designer.)
Over and over, Clarke stares down at a masking-tape mark on the floor the instant episode director Alan Taylor shouts, “Now!” Nearby, several visual-effects supervisors watch on monitors.