Sophie Turner is joining the cast of The Staircase, HBO Max's adaptation of the 2004 docuseries The Staircase, according to a report from Variety.

　　Turner joins Colin Firth, Toni Collette, Parker Posey, and more; the Game of Thrones actor will play the role of main character Michael Peterson's adopted daughter Margaret Ratliff in the eight-episode limited series.

　　The Staircase, like the docuseries before it, follows the case of author Michael Peterson (Firth), accused of murdering his wife Kathleen (Collette). Peterson claimed at the time that his wife had fallen down the titular staircase, but police suspected Peterson's involvement and he was convicted in 2003.

　　Peterson was granted a new trial in 2011, but submitted an Alford plea--the defendant maintains their innocence but agrees that the evidence would likely convict them--for a reduced charge, allowing him to be sentenced to time served and then released.

　　The original documentary was updated in 2013 and 2018, and is available right now on Netflix.

　　While Sansa Stark won't be appearing in any of them, HBO has a whole slate of Game of Thrones prequels on the way. House of the Dragon, following House Targaryen, is already in production. The Tales of Dunk and Egg, based on author George R.R. Martin's novellas following Ser Duncan the Tall and Aegon V Targaryen, is also in the works. 10,000 ships, set a millennium prior to the Game of Thrones series, just picked up its writer, and an animated series is also reportedly in development.

　　Eric Frederiksen on Google+