‘The Ritual’ revolves around the true story of Emma Schmidt, who allegedly experienced frightening blackouts, aversions to holy objects, and other unspeakable afflictions. When the psychiatric treatment didn’t help Emma much, her priest recommended “a more spiritual remedy: a solemn exorcism” in a secluded convent in rural Earling, Iowa. “The months-long ordeal would push all within the convent close to the edge of insanity, including the Priests, Sisters at the convent, and the community at large,” the logline reads.