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.