On assignment in the Middle East, television journalist Cotten Stone stumbles upon an archeological dig that uncovers the world’s most-sought-after religious relic: the Holy Grail. With his last dying breath, Dr. Gabriel Archer gives it to Cotten, uttering “You are the only one” in a language she’s heard from only one other person–her deceased twin sister.
What begins as a hot news story for the ambitious young reporter soon turns into a nightmare when the Holy Grail is stolen and strange “accidents” befall her dearest friends. Running for her life, she turns to John Tyler, a priest with firsthand knowledge of religious artifacts, for help. An anonymous source leads them to New Orleans during Mardi Gras, where an abominable experiment is underway that–unless destroyed–promises to unleash an ancient evil upon the Earth.