With Jamie Dornan and Aaron Paul already cast as the two male leads in The 9th Life of Louis Drax, the adaptation has found is female lead in Sarah Gadon.

The plot is adapted from Liz Jensen's novel of the same name, which follows Dr. Allan Pascal (Jamie Dornan), a psychologist who studies the young Louis Drax after a traumatizing fall that almost killed him on his ninth birthday. The doctor gets drawn into a mystery that pushes the limits between fantasy and reality. Aaron Paul is playing Louis' father, with Sarah Gadon set to portray the boy's mother Natalie, a role she won in a competitive casting search.

Alexandre Aja (Horns) is directing from an adapted screenplay by actor Max Minghella in his feature writing debut. Tim Bricknell and Shawn Williamson are producing alongside Alexandre Aja and Max Minghella, with Rosanne Korenberg executive producing. Shooting is scheduled to begin next month in Vancouver.

Sarah Gadon most recently starred in Enemy, The Amazing Spider-Man 2 and Belle. She will next be seen in the upcoming Dracula Untold and Maps to the Stars.