Of all the mediums and fortune tellers in Gotham City the most famous, celebrated and sought after is Madam Osiris. She does seances and personal readings, chiefly for the wealthy women of Gotham. She is of foreign extraction, either southern European or Near Eastern, no one is really sure. She uses all manner of Egyptian razzle dazzle in her seances and readings, even saying that her full name is Lady Isis Osiris Pyramidion. She has a very nice house in Crest Hill where she meets clients (when not doing house calls).
However, Madam Osiris is more than just your garden variety celebrity psychic. She also commands a quite separate organization called her Secret Circle. All manner of rumors swirl about her cult followers carrying out mystic rites, baffling crimes and atrocities across the town. Where the Secret Circle meets is unknown, other than it is not at her house.