Exclusive: Arabella Olivia Clark Calls Other Mommy Her Unicorn Role

For Clark, who has previously appeared in The Housemaid and The Hand That Rocks the Cradle, the opportunity meant stepping into the lead of a major horror film alongside Chastain, Jay Duplass and an ensemble cast that includes Dichen Lachman, Arian Moayed and Karen Allen.

“I knew I wanted to be Bela from the first audition through the final audition five months later,” Clark said. She read the script twice during the audition process, but that only made her want to know more about the story. Her mother eventually ordered Malerman’s novel for her, and Clark read that as well.

Other Mommy, produced by James Wan and made through Blumhouse and Atomic Monster, is set to release in theatres on October 9.