A young woman with no strong religious beliefs, Frankie Paige begins having strange and violent experiences, showing signs of the wounds that Jesus received when crucified. When the Vatican gets word of Frankie's situation, a high-ranking cardinal requests that the Rev. Andrew Kiernan investigate her case. Soon Kiernan realizes that very sinister forces are at work, and tries to rescue Frankie from the entity that is plaguing her.

When a young woman becomes afflicted by stigmata, a priest is sent to investigate her case, which may have severe ramifications for his faith and for the Catholic Church itself.