Sophie Turner joins Michael Peterson drama The Staircase for HBO Max

English actor Sophie Turner has been roped in to star in the limited series The Staircase which is coming to the company's streaming service, HBO Max. The plot of The Staircase follows a true story of novelist Michael Peterson. The Game Of Thrones star will play Margaret Ratliff, one of Peterson's adopted daughters. The series is written and executive produced by showrunners Antonio Campos and Maggie Cohn.