Ethan Hawke (TRAINING DAY) has joined an untitled horror film from director Scott Derrickson (THE EXORCISM OF EMILY ROSE), writes The Hollywood Reporter. Jason Blum (INSIDIOUS, PARANORMAL ACTIVITY) is producing with Automatik Ent.

Derrickson and C. Robert Cargill co-wrote the film, which is being kept top secret. Charles Layton is the exec producer.

Production will start on Sept. 19.