September 1920, the Vatican appoints Father Arno Moriani, the "Devil's Advocate", to investigate a potential candidate for sainthood in Transylvania: Martha Calugarul, who lived in the small town of Vladoviste. While staying at the village inn, Father Arno meets interesting people who help him on his search. But soon the search turns out to be different: are vampires and Dracula a myth or reality?