In promoting Game of Thrones, HBO has mastered the ability to be very intense but also reveal nothing. In teasing the show’s eighth and final season, which premieres April 2019, the network has decided to really double down on the whole A Song of Fire and Ice bit (as the books are called) and released a video that shows fire and ice each sweeping over Westeros. The ice covers a dire wolf, perhaps representing the Starks, and a dragon — hello, Viserion — while the fire rages up from the ocean like Daenerys’s forces over a Lannister-like lion into a big collision. What does it all mean? Mostly that HBO has invested a whole lot of money in one of those grade-school science-fair projects where you make a volcano.