A soothsayer was a member of the Sibylline Sisterhood in Pompeii in 79 AD. She had eyes painted on the back of her hands — a sign of the cult. She was the first of the Sisterhood to see the TARDIS, or "Blue Box", that had appeared in a prophecy. She had psychic powers from breathing in dust from Vesuvius that was converting her into a Pyrovile, and could see through time because of the rift activity there. (TV: The Fires of Pompeii)
Karen Gillan was later cast as Amy Pond, first companion of the Eleventh Doctor, played by Matt Smith, beginning in series 5; coincidentally, Amy had an affinity for Romans. Unlike other guest actors who later played more prominent characters (such as Lalla Ward or Freema Agyeman), no attempt was made, either on-screen or in behind-the-scenes interviews, to connect the soothsayer to Amy.