Deadline is exclusively reporting that the pilot for the potential Game of Thrones prequel series written by Jane Goldman and George R. R Martin will not be moving forward at HBO.

The untitled project from Goldman and Martin was set to take place thousands of years before the events of Game of Thrones, being described as chronicling “the world’s descent from the golden Age of Heroes into its darkest hour. And only one thing is for sure: from the horrifying secrets of Westeros’ history to the true origin of the white walkers, the mysteries of the East to the Starks of legend… it’s not the story we think we know.”

According to Deadline’s sources, it states in the report that Jane Goldman had been emailing the cast and crew of the project to tell them that the pilot is dead. The pilot had a cast that included Naomi Watts, Josh Whitehouse, Naomi Ackie, Denise Gough, Jamie Campbell Bower, Sheila Atim, Ivanno Jeremiah, Georgie Henley, Alex Sharp, Toby Regbo, Miranda Richardson, Marquis Rodriguez, John Simm, Richard McCabe, John Heffernan and Dixie Egerickx.

The Goldman/Martin project was one of the five Game of Thrones prequels announced to be in development at HBO in 2017, with the other projects hailing from Max Borenstein, Brian Helgeland, Carly Wray and Bryan Cogman. A few months ago, it was announced that another prequel pilot was in development, this time from Martin alongside Ryan Condal, set three-hundred years before the series and tracks the beginning of the end for House Targaryen.

It’s being stated through Deadline and TVLine sources that the pilot was screened to HBO executives over the summer and they weren’t impressed with what they saw. This led to reshoots-re-editing of the initial cut, and apparently failed to impress the execs again, leading to the demise of the project.