When the Ring was worn it granted the wearer immortality and imprisoned the wearer in the stone of Rassilon's embossing, watching over Rassilon forever. (TV: The Five Doctors) The ring could also be used to open up a hidden door in the Tomb. Rassilon possessed Leela as she wore the ring, leading her, Romana II, and K9 Mark 2 into the Matrix. (AUDIO: Zagreus)