Grace, a young eye doctor, is summoned to a remote convent in Scotland after the alleged suicide of her priest brother. Distrusting the Church's account, Grace tries to find out what really happened with the help of Vatican priest Father Romero. As she explores the convent's sepulchral cloisters, and the wild cliffs and windswept beaches nearby, she uncovers not only murder and sacrilege, but a disturbing truth about her own past which brings long-buried trauma to the surface.