Toni Collette to co-star with Colin Firth in 'The Staircase'

April 30 (UPI) -- Knives Out, Unbelievable and United States of Tara actress Toni Collette has landed a lead role in The Staircase, an eight-part, fact-based drama for HBO Max.

The Emmy and Golden Globe winner will play Kathleen Peterson, a woman whose husband, Michael, killed her and staged it to look like an accident in 2001.

Michael was convicted of murder, but the charge was later downgraded to manslaughter and he was released from prison in 2017.

Inspired by a docuseries and several books written about the case, the project will co-star The King's Speech and Supernova actor Colin Firth as Michael.

Antonio Campos is directing the series, which was written by Maggie Cohn.