In a plot twist worthy of Game of Thrones itself, HBO has decided not to move forward with the Game of Thrones prequel starring two-time Oscar nominee Naomi Watts.

Jane Goldman, showrunner on the series, emailed cast and crew to tell them that the show was no longer happening, Deadline reports. The prequel series was expected to launch sometime in 2021. We’ve contacted HBO to confirm the show’s cancellation and will update this story if we hear back.

The Watts-led series, which was set thousands of years before Game of Thrones, had already acquired a full cast and shot a pilot, which had finished filming by July of this year. At the 2019 Television Critics Association press tour, HBO chief of programming Casey Bloys told members of the press that the cast and footage looked “really, really good.”

In addition to Watts, the untitled Game of Thrones prequel starred Poldark actor Josh Whitehouse, Star Wars: Episode IX‘s Naomi Ackie, Doctor Who veteran John Simm, and a number of other familiar faces.

At least two more Game of Thrones prequel series are still in the works at HBO. One show, which is loosely based on the rise of House Targaryen as documented in George RR Martin’s A Song of Ice and Fire tie-in Fire & Blood, was said to be moving closer to a pilot order at the premium network. According to Martin, a third prequel series is also in development.

Another prequel, which was being developed by Game of Thrones writer and director Brian Cogman, was canceled last April, just as Game of Thrones‘ controversial final season was beginning to gain steam.

While the exact budget for the now-axed pilot isn’t known, HBO previously confirmed that its planned Game of Thrones prequel series would be more expensive than the flagship show. “$50 million [per season] would never fly for what we are trying to do,” Francesca Orsi, HBO’s senior vice president of drama, said in 2018.

As such, HBO probably lost quite a bit of money on the ambitious pilot, which was filmed in some of the same locations as the original Game of Thrones. Still, it wouldn’t be the first time: Game of Thrones‘ original pilot, which cost $10 million, was a complete disaster and required major reshoots before it aired in 2011.