Because of a strike at the BBC, Shada was never finished and never aired. Various attempts were made to breathe life into it as a narrated reconstruction, an audio play, and a novelization, but in 2017 the BBC released a video version with animated restoration like those done for the First and Second Doctors, the missing dialogue recorded by the surviving original cast. It is therefore a real Doctor story.
The Doctor answers a distress signal from Professor Chronotis (Denis Carey) a Time Lord living as a professor at Saint Cedd’s College, Cambridge. A mad scientist named Skagra (Christopher Neame) extracts the mind of the Professor with a spherical device. The Doctor must retrieve a dangerous Gallifreyan book the Professor had thoughtlessly loaned to a student named Chris Parsons (Daniel Hill). The Professor lives long enough to warn the Doctor, Romana, and Parsons about Skagra looking for the book and the involvement of Shada, the Gallifreyan Prison full of the worst criminals of all time.
The Doctor finds Skagra’s cloaked spaceship in a cow pasture, but Skagra uses the sphere to extract the Doctor’s mind so he can decode the book, and he imprisons the others. But the Doctor survives with his mind intact and uses the ship’s computer to release Chris and K9 and take them to a space station. Romana has been taken in the TARDIS to Skagra’s carrier ship.
Back on Earth, the Professor’s chambers are revealed as a TARDIS in disguise, when he is accidentally revived by Clare Keightley (Victoria Burgoyne), Chris Parson’s girlfriend. The book is a Key to the Prison Planet of Shada, where a criminal named Salyavin is held. Skagra needs him for his fiendish plot. Professor Chronotis and Clare, to whom he has passed knowledge of TARDIS engineering, repair his TARDIS to reach Skagra’s carrier. They save the Doctor and Chris.
Skagra has decoded the book and reveals, in the usual super-villain boast, his intention to absorb Salyavin’s powerful telepathic mind in his quest to unite all life into a universal mind, controlled by him. As Skagra releases the prisoners, the good guys reach Shada. Salyavin is not in his cell. In fact, Salyavin is Professor Chronotis. Skagra absorbs his mind and enslaves the prisoners and Chris. But the Doctor’s mind is part of Skagra’s now, and the Doctor builds a telepathy helmet to take control of Skagra, who becomes a prisoner on his own ship. The Doctor restores the criminals’ minds and returns them to Shada. He parts ways with Chronotis/Salyavin.
Writer Douglas Adams had a whole different story in mind and the producer forced him to change it, eventually coming up with Shada. It was supposed to be six episodes. Location filming in Cambridge and one studio session were completed, but a long-running dispute with BBC technicians held up production into Christmas programming and the whole thing was scrapped. In 1983, Tom Baker refused to appear in the 20th anniversary special The Five Doctors, and some clips from Shada were used to explain why that Doctor did not join in with the other four. The truth, of course, is that Tom Baker had too big an ego to appear in a less than starring role in a Doctor Who story. In fact, he felt ambivalent about the Doctor until fan-expos started to happen and he found himself lionized by adoring fans. (I am not Spock; yes, I am!) By 2017, he was happy to record dialogue for the animated reconstruction of Shada, without which it could not have happened.
The car Skagra steals to drive around Cambridge was a Ford Prefect. Parts of Shada appeared as Dirk Gently’s Holistic Detective Agency by Douglas Adams. The animated version uses music by Sylvester McCoy, the Seventh Doctor. It was the last six-part story written. I won’t miss them. Denis Carey (Chronotis) and David Brierley (K9) had passed on, so their unrecorded lines were excised from the script in the animated version. Imprisoned in Shada, apparently, were Lucretia Borgia, Boadicea, Lady Macbeth, Salome, Rasputin, Nero, Genghis Khan, a Dalek, a Cyberman, and a Zygon. The book McGuffin was entitled The Worshipful and Ancient Tale of Gallifrey. A dozen Cambridge University locations looked wonderful and most of the cast acquitted themselves with honor, the Professor and the Villain, in their different ways, particularly delightful. The story was considered a high point for Doctor Who and it’s a shame that high point was lopped off.