sentences:  In 1983, clips from "Shada" were used in "The Five Doctors", the 20th-anniversary special.Tom Baker, the fourth actor to play the Doctor, had declined to appear in the special, and the plot was reworked to explain the events in the clips.Denis Carey was subsequently cast as the eponymous Keeper in Tom Baker's penultimate story, "The Keeper of Traken" (1981), and also appeared as the Borad's avatar in "Timelash" (1985).