Burdened by spring floods malaria and yellow fever citizens of New Orleans often turned to voodoo practitioners-African Rosalie Sanite Dede Bras Coupe-for protection. None was more powerful or feared than Doctor John or Marie Laveau. After P.I. Wyatt Thomas encounters a ghost during a hospital visit he tells the story to his sometimes business partner voodoo mambo Mama Mulate. She puts him in a trance and channels the ghost soon learning a curse connects him and a long-dead French aristocrat. They are doomed to remain connected forever unless Wyatt can return to old New Orleans and lift the curse before midnight on New Year''s Eve.