This supernatural drama follows the life of a 25-year-old nun named Sister Ann who feels that she has a special gift for performing exorcisms. She desires to help, but is hampered by the fact that only priests are allowed to perform exorcisms. When one of her mentors notices that she may have what it takes to help, she is allowed as an observer at first. But Sister Ann's gift will eventually be tested when she encounters dark forces that have ties to her life in the past.