High Priestess (The Fires of Pompeii)

The High Priestess was in charge of an ancient sisterhood called the Sibylline Sisterhood that were hired by the city of Pompeii to see the future. When she was younger she was possessed by the Pyrovile force by breathing in volcanic dust and her body slowly turned into stone. She, like the rest of the sisterhood, had a telepathic link to the other sisters in her order as well as several other citizens of Pompeii, such as Lucius Petrus Dextrus and a young woman called Evelina. Donna Noble told Evelina of the events that were due to come and refered to them as a new prophecy. She said that Mount Vesuvius would erupt, destroying pompeii. The High Priestess insisted that there was only one prophecy and ordered the sisterhood to make the 'False Prophet surrender with her last breath'. The High Priestess had a plan to convert humans into Pyrovile in order to keep them from extinction and then boil the oceans away, taking over Earth and all civilization. She died as a result of Mount Vesuvius erupting and destroying her along with Pompeii. (DW: The Fires of Pompeii)