Deadline reports, Golden Globe winner Sarah Paulson and Emmy nominee Elle Fanning have signed on for a new adaptation of I Am Sybil, Flora Rheta Schreiber’s best-selling 1973 nonfiction novel. The project will center around one of the first mainstream cases of dissociative identity disorder.

Paulson gained recognition for her many collaborations with award-winning series creator Ryan Murphy, which began with American Horror Story. On top of I Am Sybil, she’ll star in Searchlight Pictures’ upcoming horror thriller Dust.

Meanwhile, Fanning recently reprise her role acclaimed role as Catherine the Great in Hulu’s The Great Season 2. Additionally, the Maleficent actress has also recently signed on to join the casts of Rosebushpruning with Kristen Stewart and Bob Dylan biopic A Complete Unknown with Timothée Chalamet.

Who’s Involved in I Am Sybil?

The movie will be directed by Mirrah Foulkes from a script she co-wrote with Jen Silverman. The film is expected to explore the “gripping true story” of Shirley Mason a.k.a Sybil who was examined by psychologist Connie Wilbur. During her therapy sessions, she allegedly manifested sixteen personalities.

I Am Sybil was first developed into a TV movie in 1976, which starred Sally Field and Joanne Woodward. The project will also be based on Debbie Nathan’s 2011 book Sybil Exposed: The Extraordinary Story Behind the Famous Multiple Personality Case.