The First Prophecy marks the prelude to the classic horror film The Prophecy (1976). The new plot follows young American Margaret (Nell Tiger Free), who is sent to Rome to live in the service of the church. There, she becomes fond of Carlita, a quiet and alone young woman, who also lives in the convent. When questioning the girl’s past and situation to the other sisters in the church, she is warned to stay away. However, before following the advice, she is faced with a darkness that makes her question her faith. With the help of a defrocked priest, she ends up discovering a dark conspiracy, which for years was hidden by the local church, which tried to hide the inevitable: the return of evil incarnate, the so-called antichrist.