Accused of killing her baby, Stephanie Daley (Amber Tamblyn) insists that she is innocent of the charges. Lydie Crane (Tilda Swinton) is the psychologist hired by the prosecution to determine Stephanie's competency, a task complicated by the fact that Lydie is grieving the loss of her own stillborn child. Knowing she has a job to do, Lydie must get to the root of Stephanie's motivations and state of mind while grappling with her own emotional and psychological demons.