It hasn't even been a month since the final episode of Game of Thrones aired—which, by the way, even the actors and actresses of the HBO show are still processing. But the network is wasting no time on their potential replacement. The Game of Thrones prequel, which does not yet have an official title—though the book series' author, George R.R. Martin, has hinted may be called The Long Night—has already started filming.

The next Game of Thrones is being made in a place that's very familiar to fans of the original series: Northern Ireland. This time, though, the King of the North will look a lot different from Robb Stark, or even Sansa Stark. That's because this series will be set about 5,000 years before Cersei and Jaime Lannister set in motion the series of events depicted on the show. Much to the dismay of Sansa Stark fans, this is the only Game of Thrones spinoff we'll be getting—at least for the time being—as Sophie Turner recently ruled out returning to the screen as her character.

As for the Game of Thrones prequel, other than the fact that it's being filmed in Northern Ireland, details are being kept characteristically vague. What we do know is that only the pilot is currently shooting and, if HBO indeed orders it, then it will be an even longer wait until the new series is out. (It likely won't run before 2021.) We also know that the plot will take place well before the Iron Throne even existed.

“Westeros is a very different place,” Martin told Entertainment Weekly last fall. “There’s no King’s Landing. There’s no Iron Throne. There are no Targaryens—Valyria has hardly begun to rise yet with its dragons and the great empire that it built. We’re dealing with a different and older world and hopefully that will be part of the fun of the series.”

As for the people working on the show other than Martin, expect Naomi Watts, Naomi Ackie, Denise Gough, Miranda Richardson, Josh Whitehouse, Jamie Campbell Bower, Sheila Atim, Ivanno Jeremiah, Alex Sharp, and Toby Regbo in the cast. Behind the scenes Martin is working alongside the director S.J. Clarkson, of Jessica Jones, and the showrunner Jane Goldman.