Toni Collette will star alongside Colin Firth in the HBO Max limited series “The Staircase,” Variety has learned.

The eight-episode series is based on the docuseries of the same name as well as various books and reports about the case of Michael Peterson (Firth), who was accused of murdering his wife, Kathleen (Collette), in 2001. He claimed she died after falling down the stairs at their home, but police suspected he bludgeoned her to death and staged the scene to look like an accident.

Collette is one of the most celebrated actresses working today, with numerous critically-acclaimed performances in both film and television. In TV, she most recently starred in the Netflix series “Unbelievable” and will also star in the streamer’s upcoming drama “Pieces of Her.” She won an Emmy in 2009 for her starring role in the Showtime series “United States of Tara,” while she picked up a Golden Globe for the show the next year.

In film, Collette had a role in the hit Rian Johnson film “Knives Out” and is also known for starring in features such as “The Sixth Sense” — which earned her an Oscar nomination for best supporting actress — as well as “Muriel’s Wedding,” “Hereditary,” “Little Miss Sunshine,” “About a Boy,” and “Tsunami: The Aftermath.”

Collette is repped by CAA, United Management, and Finley Management.

“The Staircase” was picked up to series at HBO Max in March. It is written and executive produced by showrunners Antonio Campos and Maggie Cohn. Campos will also direct six of the eight episodes. The series is a co-production between HBO Max and Annapurna Television.