Doctor Who: Shada (Ep)

The Doctor, Romana and K·9 visit an old friend, a retired Time Lord named Professor Chronotis now living as a professor in Cambridge. There they encounter the evil scientist Skagra, who has come to steal a Gallifreyan text in Chronotis' possession. With the book, Skagra can locate Shada, the Gallifreyan prison planet, where he intends to force Salyavin, a Time Lord criminal with vast mental powers, to help him imprint his mind upon every being in the cosmos.