Shada (TV story)

Shada was the intended final story of Season 17 of Doctor Who. It was to be the final story written by Douglas Adams for the series, the final six-part story until TV: Dreamland in 2009, and the last story to feature Graham Williams as producer, as John Nathan-Turner would take over after this until the end of the series run in 1989.

However, a combination of rampant inflation in Britain and union strikes halted production partway through filming. The story would become infamous for its incomplete nature and would lead to several attempts to create stories using the unpublished material. It was the basis for, a non-Doctor Who book published by Adams in 1987 that was the start of the Dirk Gently book series.

The parts of the story that were filmed were retained, and John Nathan-Turner was able to reuse them later in two notable ways. In 1983, a few clips of the show were integrated into TV: The Five Doctors for the scenes with the Fourth Doctor when Tom Baker proved unavailable for filming. Later, in 1992, the existing footage was integrated with some new linking narration by Baker for a special BBC Video release. Finally, in 2017, a completed cut was released, including animations of missing scenes featuring many of the original actors, and even some newly filmed scenes.

The story finally was aired on television for the first time on 19 July 2017, on BBC America. This marked 37 years, 9 months and five days between the beginning of filming and the airdate, a record for any episode of Doctor Who.

Synopsis
Shada: a prison built by the Time Lords for defeated would-be conquerors of the universe. Skagra, one such inmate, needs the help of one of the prison's inmates. He finds nobody knows where Shada is anymore, except one aged Time Lord who has retired to Earth, where he is a professor at St. Cedd's College. Luckily for the universe, Skagra's attempt to force the information out of Professor Chronotis coincides with a visit by the professor's old friend, the Fourth Doctor.

Part one
On the Think Tank space station, a scientist named Skagra uses a spherical device to drain the minds of his colleagues and departs in his spaceship for Earth, leaving an automated, repeating quarantine message running: "This is a recorded message. The Foundation for the Study of Advanced Sciences is under strict quarantine. Do not approach. Do not approach. Everything is under our control."

At St Cedd's College in Cambridge, 1979, Professor Chronotis has a visit from one of his students, Chris Parsons, who leaves with the wrong book. The Doctor and Romana are enjoying a spot of punting. They're observed by Skagra and distracted by voices from the sphere he's carrying. They visit the Professor.

In the physics lab, Chris discovers that the book is written in a completely alien script. He analyses the book with instruments that make it smoke and glow. Chronotis reveals to Romana he is an elderly Time Lord who has retired to Earth and has been living in the same Cambridge rooms for three hundred years. The Doctor asks him why he was summoned by him to Cambridge but the Professor can't remember. He later recalls he needs the Doctor's help finding the book.

Wilkin, the college porter, is updating a notice board when Skagra — dressed in a distinctive white and silver outfit, with a wide-brimmed hat — arrives and arrogantly demands to see Chronotis. Naturally, Wilkin takes a dislike to this ill-mannered stranger and tells him the Professor will not want to be disturbed; he is with the Doctor, a "very old friend". A rebuffed Skagra leaves.

Skagra steals a car and the driver's ability to drive. The Professor reveals the missing book is one he brought from Gallifrey. Skagra drives out to a field where his spaceship is concealed, invisible to the human eye. The Professor confesses the book he took was The Worshipful and Ancient Law of Gallifrey, which dates back to the time of Rassilon and has incredible power. Skagra receives word that all is ready from his carrier ship, commanded by a massive Krarg...

Part two
The Doctor and Romana search the Professor's rooms for the book. They discuss Time Lord law. This reminds them of the Time Lord criminal Salyavin, a boyhood hero of the Doctor. The Professor, asked about his contemporary Salyavin, recalls Chris Parsons' visit and wonders if he has borrowed the book by accident.

Chris and his friend Clare Keightley analyse the book as the Doctor cycles across Cambridge to the lab. Skagra, now wearing the car driver's contemporary clothes, comes to the Professor's college seeking him. While Romana looks in the TARDIS for milk so they can have tea, Skagra arrives for the book. He sets the sphere on the Professor, stealing part of his mind. The Doctor meets Clare at the lab, and examines the book.

Romana and K9 Mark II find the collapsed Professor as Chris Parsons arrives. Using the TARDIS medical kit, Romana tries to stabilise the Professor's condition. The Doctor and Clare discover that the book carbon dates as minus twenty thousand years old. Skagra scans his copy of Professor Chronotis' mind for a trace of the book but finds nothing. The professor beats out a message to Romana on his hearts in Gallifreyan morse code, telling her to beware of the sphere, Skagra and Shada, but dies before he can reveal where the secret is.

Skagra meets the Doctor trying to return the book to the Professor and has a sphere pursue him on a bike through Cambridge. During the chase the book is dislodged from his basket and retrieved by Skagra. Forced to run away, the Doctor is cornered by the sphere. He tries to escape under a gate, but the sphere approaches and begins to steal his mind...

Part three
Romana arrives in the TARDIS to rescue the Doctor. In Chronotis' rooms, Chris moves to close the Professor's still-open eyes, which are troubling him, but as he tries to do so, the body vanishes. The TARDIS returns, and Chris tells the Doctor and Romana what happened. The Doctor says Chronotis must have been on his very last regeneration, and decides he needs to speak with Skagra. K9 tracks the sphere to Skagra's ship. Clare, worried about the danger the book may pose, comes to Chronotis' rooms to find them empty. Scared, Clare runs out and comes across Wilkin, telling him about the "dangerous" book but he naturally finds her tale hard to believe. However, Wilkin offers to see if he can locate Chronotis, and Clare goes back to the Professor's rooms.

The TARDIS materialises in an apparently empty field which holds Skagra's invisible ship. They enter and suddenly, Romana, K9 and Chris vanish in a cube of light; Skagra has taken them prisoner. He tells them he was interested only in Chronotis' mind. He tries to force the Doctor to decode the book and sets the sphere on him to take his mind. K9 fails to blast out of the cell he, Romana and Chris are held in. K9 picks up the Sphere's signals and detects the Doctor amongst its voices. Suddenly, the cube of light transports Romana from the cell, leaving Chris and K9 behind. Romana is taken to the TARDIS by Skagra, who forces her to take it.

While searching the Professor's rooms for the missing book, Clare finds concealed control panels and accidentally triggers an explosion. The Doctor awakens on the ship and explains to its computer how he survived. The sphere took only a copy of his mind.

Wilkin comes to the Professor's rooms to tell Clare he has been unable to find Chronotis. He knocks, but there is no answer. Wilkin opens the door, only to find not the room but the swirling time vortex. The Doctor tries to persuade the Ship to release his companions and him, but it decides the sphere must haves succeeded in its task and killed the Doctor. To conserve resources, the Ship turns off the oxygen supply, As the Doctor collapses slowly to the floor, the ship states "Dead men do not require oxygen..."

Part four
The cube of light transports Chris and K9 from the cell. The Ship detects them and reactivates its oxygen supply, announcing "Oxygen levels returning to normal." The TARDIS arrives at the Krarg carrier ship and Romana sees the Krargs being grown in a generation annexe. Another Krarg starts to form in a smaller version of the generation annexe on Skagra's ship. The Doctor boosts the Ship's power to allow it to cross space quickly.

In Professor Chronotis' rooms, Clare awakes. She is startled by the Professor, dressed in an old-fashioned nightcap and nightshirt. Skagra is unable to translate the book with the Doctor's mind in the sphere. The Professor explains to Clare that his rooms are his TARDIS and it interfered to save his life.

The Professor decides they must find Skagra to save the book, which is the key to Shada, the Time Lord prison which has been forgotten. The Doctor and Chris are attacked by a Krarg, but K9 holds it off, allowing them to explore the Think Tank complex where they have arrived. (The automated quarantine message is still playing, but is now naturally worn and distorted.) They find the aged, mindless figures of Skagra's former colleagues.

Skagra notices that turning the pages of the book influences the TARDIS. He realises turning the last page of the book will take him to Shada where he will find the Time Lord criminal Salyavin, who is crucial to his plans.

The Doctor attaches Chris to the mind resource console to link Chris's intelligence reserves to the memory patterns of one of the scientists, the neurologist Caldera; Chris passes out when the Doctor activates the console. Caldera explains to the Doctor how Skagra — or "Dr. Skagra", as he was known to them — set up Think Tank with himself, A. S. T. Thira, G. V. Santori, L. D. Ia and R. F. Akrotiri to pool the resources of the mind electronically, but when they had completed the sphere he used it to steal their minds. Skagra now intends to use his mind to dominate the whole of humanity, but needs Salyavin to accomplish this. Caldera then passes out and the Doctor checks on Chris, who comes to. K9 loses his fight against the Krarg and is driven into the Think Tank by the massive creature, which now advances on the Doctor...

Part five
The Krarg strikes the machinery in the Think Tank, creating explosions and a huge cloud of smoke, before it strikes down and kills the scientists. This allows the Doctor, K9 and Chris to escape back to Skagra's ship, leaving just as the Think Tank station explodes. The Ship is persuaded to take the Doctor to Skagra's home.

While trying to repair the Professor's ship Clare asks who Salyavin is. The Professor places the knowledge that Clare needs to repair the TARDIS in her head telepathically. Skagra's ship takes the Doctor's ship to the Krarg carrier ship. They are captured and Skagra reveals his plan to take over the universe telepathically, merging them into one mind: his. The Doctor stages an escape with Chris and K9, but Romana is dragged back to the TARDIS by Skagra.

Fleeing down the corridors of the ship the Doctor and company find an old wooden door and go through it. They are in Professor Chronotis' rooms/TARDIS. The Professor knows that with the book and the Doctor's TARDIS, Skagra can travel to Shada, which is exactly what he does. Skagra searches Shada's records for Salyavin, the Time Lord criminal.

The Professor's TARDIS arrives with K9, the Doctor and him. Skagra revived the following prisoners in chamber T when the Doctor arrives: the orange insectoid #547, the Boudica-like #595, the cyborg #590, the Nero-like #512, the Genghis Khan-like #568, the Rasputin-like #504 and the purple man #503. Among the cryogenic cells' shadows also are an Ice Warrior and a Zygon silhouettes. But when Skagra opens Salyavin's cell, cabinet 9, they find it empty. The Professor admits he is Salyavin: he escaped centuries ago and used his powers to make the Time Lords forget about Shada.

The Sphere attacks the Professor, but is destroyed by K9. However, it reforms into several smaller spheres — one of which attaches itself to the Professor, who sinks to the floor. The spheres then attach themselves to the revived prisoners, bringing them under Skagra's control. Chris and Clare arrive, but Chris is taken under the control of a sphere. Skagra tells the Doctor they will now deal with him. The prisoners, along with Chris, advance menacingly towards the Doctor...

Part six
K9 fires at the prisoners, driving them back, but he is picked up and thrown aside by a Krarg. The Doctor, Romana and Clare grab K9 and flee to the Professor's TARDIS. Romana reminds the Doctor that his mind is inside Skagra's machine too. Skagra returns to the TARDIS and tells the former prisoners that they will return to the carrier ship and be distributed through the universe to further his revolution.

The Doctor follows his TARDIS in the Professor's. He captures it in a force field and has himself placed into the Time Vortex. The Doctor begins crossing to his TARDIS, but his journey appears in vain. An accident occurs in the Professor's TARDIS, deactivating the force field, throwing the Doctor into the vortex.

The Doctor finds himself in a workroom in his TARDIS, where he starts building a helmet-shaped device from various components he gathers together, as well as a chunk of tabletop. The Professor's TARDIS arrives on the carrier ship as the Doctor — wearing the ridiculous-looking helmet — reveals himself and struggles for control of the joint mind.

Romana deactivates the Krarg generating equipment, tipping the gas out and using it to destroy the Krargs. Skagra flees to his ship, but the cube of light transports him to the cell Romana, K9 and Chris were held prisoner. He demands the Ship lets him out, but the Ship tells him it can no longer accept his orders as it has now decided to serve the Doctor. The Ship offers to tell its former master all about the Doctor; Skagra responds by sinking to the floor, sobbing "Let me out! Let me out!" The Ship chuckles.

The Doctor promises to return the prisoners to Shada and summon the Time Lords. He returns his and the Professor's TARDISes to Earth. This confuses Wilkin, who has returned with a policeman to find the room back in its usual place and the Professor taking tea with his guests. The policeman then spots the TARDIS and asks about it. The Doctor says it's his, and he and Romana say goodbye to everyone and leave in the TARDIS. After the TARDIS has dematerialised, the policeman asks where the police box has gone. When Chronotis replies "What police box would that be, officer?", the policeman — having had enough of stolen rooms and disappearing police boxes — tells everyone to get their coats on; they're coming with him "down to the Bridewell", i.e. the police station.

Aboard the TARDIS, the Doctor and K9 are tinkering under the console; and Romana asks where Skagra was from, to which the Doctor responds he was from the planet Dronid — according to K9's analysis. Suddenly, a small explosion occurs under the console. Romana then asks if the stories about Salyavin were exaggerated by the Time Lords, since the Professor seemed like a nice old man to her. The Doctor says the Time Lords overreact to everything, and wonders if someone will meet him 200 years in the future and ask themselves: "Is he really the Doctor? How strange. He seems such a nice old man." The Doctor then emerges from under the console, to reveal that the explosion has aged him greatly...!

Cast

 * Doctor Who - Tom Baker
 * Romana - Lalla Ward
 * Skagra - Christopher Neame
 * Chris Parsons - Daniel Hill
 * Professor Chronotis - Denis Carey
 * Clare Keightley - Victoria Burgoyne
 * Voice of K9 - David Brierley
 * Wilkin - Gerald Campion
 * The Ship - Shirley Dixon
 * Caldera - Derek Pollitt
 * Voice of the Krargs - James Coombes
 * Police Constable - John Hallett
 * Man in Car - David Strong
 * Fisherman - James Muir
 * Krargs
 * Derek Suthern
 * Barnaby Edwards
 * Doctor's Body Double - Tim Bentinck (2017 DVD release)
 * Continuity Announcer - Toby Hadoke (2017 DVD release)

Crew

 * Writer - Douglas Adams
 * Continuity Announcer - Toby Hadoke
 * Production Unit Managers
 * John Nathan-Turner
 * Kathleen Bidmead
 * Production Assistant - Ralph Wilton
 * Director's Assistants
 * Olivia Bazalgette
 * Jenny Doe
 * Assistant Floor Manager - Val McCrimmon
 * Floor Assistant - Barabara Jones
 * Incidental Music & Sound Design - Mark Ayres
 * Title Music written by Ron Grainer & Realised by Delia Derbyshire
 * Special Sound
 * Brian Hodgson
 * Dick Mills
 * BBC Radiophonic Workshop
 * Sound Recordist - Ron Blight
 * Studio Sound
 * John Hartshorn
 * Michael McCarthy
 * Film Camera
 * Fintan Sheehan
 * Colin Case
 * Miniatures Photography - Peter Tyler
 * First Assistant Camera - Chris Hayden
 * Gaffers
 * Alan Graham
 * Dave Scrivens
 * Grip - Stan Sweetman
 * Lighting Electricians
 * Paul Barlow
 * Tony Edwards
 * Studio Camera Supervisor
 * Alec Wheal
 * Dicky Howett
 * Studio Lighting
 * Mike Jefferies
 * Martin Kempton
 * Lighting Console Operator - Stephen Emmett
 * Set Construction
 * Mark Barton Hill
 * Kevin Chapman
 * Offline Editor & First Assistant Director - John Kelly
 * Film Editor - Tariq Anwar
 * Vision Mixer - James Gould
 * Film & Video Remastering - Peter Crocker
 * Animation Character Art - Martin Geraghty
 * Lead Animator & Animation Supervisor - AnneMarie Walsh
 * 3D Animation & Compositing - Rob Ritchie
 * Lead Animation Colourist & Storyboards - Adrian Salmon
 * Animators
 * Ana García Sebastia
 * Joanna Hepworth
 * Barry Evans
 * Shaun Askew
 * David Busch
 * Robin Brindle
 * Linda Kalcov
 * Andy Gubba
 * Chris Bowles
 * Barry Baker
 * Jane Davies
 * Kate Sullivan
 * Animation Background Artists
 * Colin Howard
 * Graham Bleathman
 * Additional Storyboards
 * Mike Collins
 * Jez Hall
 * Assistant Animation Colourist - Alan Craddodck
 * Visual Effects Designer - Dave Havard
 * Miniature Effects Supervisor - Mike Tucker
 * Senior Effects Technician - Nick Kool
 * Additional Model Making
 * Jonathan Sellers
 * Philip Robinson
 * K9 Operators
 * Nigel Brackley
 * Mat Irvine
 * Visual Effects Assistant - Roger Turner
 * Electronic Effects - Dave Chapman
 * Production Designer - Victor Meredith
 * Design Assistant - Les McCallum
 * Prop Buyer - Helen MacKenzie
 * Costume Designer - Rupert Roxburghe-Jarvis
 * Costume Restoration - Robert Allsopp
 * Make-ups
 * Kim Burns
 * Sinikka Ikaheimo
 * Joan Stribling
 * Special Thanks
 * Steve Roberts
 * Clayton Hickman
 * Lydia Butz
 * Peter Ware
 * Andrew Martin
 * Gavin Rymill
 * Roger Dilley
 * Helen Dilley
 * Brad Kelly
 * Karen Parks
 * Andrew Pixley
 * William Delauney
 * Legal & Business Affairs - Linda Duncan
 * Production Finance - Jo Blaylock
 * Producer - Graham Williams
 * Director - Pennant Roberts
 * Executive Producers for BBC Worldwide
 * Paul Hembury
 * Rebecca Richmond
 * Produced & Directed by Charles Norton
 * Dedicated to Dudley Simpson (1922-2017)

Uncredited crew

 * Animator - Michael Dinsdale (DWM 520)

The Doctor

 * The Doctor received an honorary degree from St. Cedd's College, in 1960. He visited Professor Chronotis in 1955, 1960 and 1964 in his fourth incarnation, and also in 1958 in a previous incarnation.

Planets

 * Skagra's home planet is Dronid.

TARDIS

 * Chronotis recognises the Doctor's TARDIS as a Type 40, and claims they had been built when he was a youth.
 * Chronotis mentions the TARDIS kitchen.
 * Chronotis' TARDIS has a conceptor geometry relay, with magranomic trigger, as well as a defunct field separator, but this won't be needed if they can fix the interfacial resonator.
 * The Doctor goes vortex walking between Chronotis' and his own TARDIS.
 * Chronotis' TARDIS is an older model. Its chameleon circuit disguises it as a door leading into Chronotis' rooms, while the control panel is hidden by a wall.
 * Chronotis salvaged his TARDIS from a scrapyard.

Theories and concepts

 * Chronotis' memories are extracted through psychoactive extraction.

People from the real world

 * Whilst punting down the river, the Doctor mentions Isaac Newton while rambling to Romana.

Time Lords

 * Salyavin was a notorious, mind-controlling criminal and a semi-hero of the Doctor's in his youth. He was sentenced for "mind crimes" to the Time Lord prison Shada.
 * Chronotis was on his last regeneration when he died, but he is brought back to life by Clare mucking around with his TARDIS.
 * The Worshipful and Ancient Law of Gallifrey dates back to the days of Rassilon, and is one of the "artefacts".
 * Chronotis is able to beat out a message with his hearts in Gallifreyan Morse code.
 * Retired Time Lords are not allowed to have access to a TARDIS.

Story notes

 * Douglas Adams chose Cambridge as a setting so he could draw on his experiences as a student at the university.
 * The story takes place in October 1979. Coincidentally, that is the same month Douglas Adams published his first The Hitchhiker's Guide to the Galaxy novel. It was also during production that Doctor Who Weekly launched.
 * Douglas Adams later used elements from this story in his novel,.
 * The cast for Shada's prisoners, though not called back for the eventual release, was originally intended to be: (DWM 267)
 * Lucretia Borgia - Ann Lee
 * Boedicia - Joan Harsant
 * Lady Macbeth - Shirley Conrad
 * Salome - Julie La Rousse
 * Executioner - John Cannon
 * Rasputin - Derek Moss
 * Nero - Barry Summerford
 * A Gladiator - Steve Kelly
 * Genghis Khan - Dave Cooper
 * Space monsters (Dalek, Cyberman, Zygon)
 * Steve Ismay
 * Ridgewell Hawkes
 * Les Shannon
 * Those scheduled to perform the Krargs in the remaining unshot scenes were: Harry Fielder (Krarg Commander), Reg Woods, Lionel Sansby and James Muir. (DWM 267)
 * Those scheduled to perform the Lab technicians in the unshot scenes were: Roger Neate and Nicky Ryde. (DWM 267)
 * Doreen James was supposed to design the costumes, but she'd quit the series following a dispute with Lalla Ward on TV: City of Death.
 * The famous scene where the Doctor is chased by the orb while on a bicycle was supposed to take place at night.
 * Douglas Adams named the characters of Chris Parsons and Clare Keightley after his friend Chris Keightley, president of the Cambridge Footlights.
 * The Thinktank scientists all bore names associated with Greek islands: Caldera, Akrotiri, Ia, Santori and Thira.
 * The part one joke in which Professor Chronotis forgets that he has a mind like a sieve was taken from a story of Douglas Adams's that had been published in the February 27th, 1965 edition of Eagle and Boy's World, when he was just twelve years old.
 * Graeme MacDonald suggested a romantic subplot between Romana and Chris, but this was ignored.
 * Michael Hayes was originally supposed to direct.
 * While in a pub, Tom Baker and Pennant Roberts were approached by the secretary of the St John's Choristers, who enquired as to whether Doctor Who might make use of his choir's services. Roberts agreed and included the Choristers — singing "Chattanooga Choo-Choo" — as part of the chase scene the next day; Baker was made an honorary fellow of St John's College in return.
 * When Skagra examines the Doctor's life, brief clips from TV: The Pirate Planet, The Power of Kroll, The Creature from the Pit, The Androids of Tara, Destiny of the Daleks and City of Death are shown. Romana I is visible in some of the clips, marking one of only two times that both Romanas appeared in the same television story (the other being the pre-regeneration flashbacks at the end of TV: Logopolis).

A lost story

 * Shada was initially not completed due to "labour action" at the BBC. The footage that was shot was released on BBC Video in 1992, featuring linking narration by Tom Baker to complete the story.
 * The industrial action occurred due to conflict over which union had jurisdiction over the operation of an elaborate clock that was featured on the BBC children's programme (1964-1988). (DOC: A Matter of Time)
 * Douglas Adams was happy that the story was abandoned, because he thought it was not up to much. In 1992, Adams signed the video rights for Shada by mistake — allowing the BBC to make a direct-to-video version, with linking narration by Tom Baker. Subsequently, Adams requested that his name be removed from the video sleeve and donated his royalties to Comic Relief. (See also VHS releases below.)
 * Had this story been broadcast when originally intended (from 19 January to 23 February 1980), this story would have marked the end of the following features of the show:
 * The 1967 arrangement of the Doctor Who theme by Delia Derbyshire.
 * The tunnel opening sequence by Bernard Lodge and the diamond series logo introduced in TV: The Time Warrior.
 * Graham Williams' tenure as producer; the rest of the show's original run would be produced by John Nathan-Turner.
 * Douglas Adams's tenure as script editor.
 * Dudley Simpson's tenure as incidental music composer (the 1992 and 2017 versions use incidental music by Sylvester McCoy-era composers Keff McCulloch and Mark Ayres, respectively, the latter version featuring music done in the style of Simpson's work).
 * David Brierley as the voice of K9; John Leeson would reprise the role the following season onwards.
 * The Fourth Doctor's multi-coloured scarf and brown frock coat; the following season would feature the Doctor (in Tom Baker's final season on the show) in a burgundy & purple scarf and a larger burgundy frock coat.
 * The TARDIS prop designed by Barry Newberry; the next nine years of the show's original run would utilise a new, fibreglass prop designed by Tom Yardley-Jones.
 * The use of six-part stories; all future serials would span four parts at most.
 * One working title for this story was "Sunburst".
 * Chronotis originally perished in part two, but Douglas Adams had become fond of the character and decided to bring him back.
 * Daniel Hill, who played Chris Parsons, met his future wife Olivia Bazalgette (she was the production assistant) during the location filming of this story. They married two years later.
 * The story would be remade in 2003 and released as WC: Shada and AUDIO: Shada, explaining that Borusa's meddling in the Fourth Doctor's timeline during TV: The Five Doctors caused the events following his and Romana's arrival in Cambridge to not take place until the Eighth Doctor and Romana came back to complete them.

Recreation

 * In 2017, a completed version of Shada was finally released, with unfilmed scenes replaced with animation and dialogue recorded by the original cast.
 * Due to the actors David Brierley and Denis Carey having passed away in the years since the original studio shoots, a few changes had to be made regarding unfilmed scenes featuring their characters — specifically, a scene with K9 in the TARDIS was cut completely (his dialogue in the finished product is minimal and consists entirely of archival audio of Brierley), and Professor Chronotis is completely silent in the scene in which he appears on Shada, communicating solely through nonverbal telepathy; him revealing himself to be Salyavin was rewritten so that the Doctor is the one to say it, using recycled audio of Carey's role as the Keeper from TV: The Keeper of Traken to provide Chronotis' response in the affirmative.
 * Discounting the non-canon TV: Dimensions in Time special in 1993, a series of in-character advertisements in 1997, and his appearance as the Curator  in TV: The Day of the Doctor in 2013, Tom Baker's appearance as the Fourth Doctor at the end of the recreation marked his first official televised portrayal of the role since TV: Castrovalva in 1982.
 * The TARDIS interior scenes used the season 20 console constructed for the 50 Years trailer. It had been restored by Mark Barton Hill with components of the original console he collected along the years and was also on display at the Doctor Who Experience (London/Cardiff) until it closed down'.
 * There was another minor change during the scene in part two where Romana emerges from the TARDIS with a bottle of milk. Her original dialogue was "I've got the milk! Come on, K9", but this was changed to "I've got the milk! Professor?" However, K9's reply of "Coming, Mistress" was strangely retained.
 * This story was later released as part of The Animation Collection.

Myths

 * Professor Chronotis' TARDIS is a Type 39. The type and model of Chronotis' TARDIS is not specified in the script or the surviving footage. In the 2012 novelisation by Gareth Roberts, the Doctor identifies it as a "Type 12, Mark 1".

Filming locations

 * The Backs, River Cam, Cambridge
 * Clare Bridge, River Cam, Cambridge
 * Silver Street, Cambridge
 * Trumpington Street, Cambridge
 * Grantchester Meadows, Grantchester, Cambridgshire
 * Free School Lane, Cambridge
 * Bridge Street, Cambridge
 * Portugal Place, Cambridge
 * Trinity Lane, Cambridge
 * Botolph Lane, Cambridge
 * King's Parade, Cambridge
 * St Edward's Passage, Cambridge
 * High Street, Grantchester
 * Emmanuel College, St Andrew's Street, Cambridge
 * Blackmoor Head Yard, Cambridge
 * Garret Hostel Lane, Cambridge
 * Portugal Street, Cambridge
 * All of the above location filming in Cambridge took place over a period of five days: 15th to 19th October 1979
 * Ealing Television Film Studios (Stage 2), Ealing Green, Ealing
 * BBC Television Centre (Studio TC3), Shepherd's Bush, London

Production errors

 * When Chronotis says "Undergraduates" as Skagra is knocking on his door, voices from the sphere should be heard but they are not present in the final release.
 * When Professor Chronotis is attacked by Skagra's sphere in part two, his spectacles appear and disappear depending on the camera angle.
 * When Romana rescues the Doctor with the TARDIS, at the beginning of part three, the end of the scarf gets caught in the door. Moments later the TARDIS materialises in the Professor's rooms, but the end of the scarf is no longer hanging out the door.

Continuity

 * While punting, the Doctor and Romana are captured by Borusa, only to be returned after being trapped in the space time continuum. (TV: The Five Doctors)
 * The First Doctor first met Chronotis in Cambridge in an unspecified year implied to be the 1958 visit. (PROSE: Cambridge Previsited) In another account, the Third Doctor went to see Chronotis in 1958. (PROSE: The Time Lord Letters)
 * In the room where the Doctor builds his helmet are also stored: the Trilogic game, (TV: The Celestial Toymaker) a Cyberman head, (TV: The Invasion) his time sensor, (TV: The Time Monster) some Metebelis crystals, (TV: The Green Death) a Laserson probe, (TV: The Robots of Death) the Polyphase Avatron, (TV: The Pirate Planet) a Movellan gun and Dalek bomb, (TV: Destiny of the Daleks)  Kerensky's time travel equipment, (TV: City of Death) and the Tythonian communicator. (TV: The Creature from the Pit)
 * The Doctor would use the The Worshipful and Ancient Law of Gallifrey again in his seventh incarnation. (PROSE: The Dimension Riders)
 * In C. S. Lewis' short story The Professor, the Queen and the Bookshop, there was a book named Shada. (COMIC: The Professor, the Queen and the Bookshop)

VHS releases
In 1992, BBC Video released a version compiling existing footage broken down into the planned six episodes, with linking narration by Tom Baker in the part of a fourth-wall-breaking incarnation of the Doctor reminiscing about this earlier, "cancelled" adventure from his youth while wandering through a museum of the Doctor's enemies. In actuality, this linking material was recorded in a Doctor Who-themed exhibition called "Behind the Sofa" at the Museum of the Moving Image, London. Footage and still photos of a Krarg mannequin from the museum was further used in the linking sequences to represent the Krargs in the story.

No writer's credit for Douglas Adams, or any other references to him, appeared on the video sleeve — aside from a sticker reading "All of Douglas Adams' royalties from the sale of this video are being donated to Comic Relief." (original printed text)

The UK release of the video included a book containing the full script of the original production; the North American release did not include the booklet. Unfortunately, the book's first two pages were transposed, so the Doctor Who diamond logo appeared on the second page instead of being visible through the appropriately-shaped hole in the front cover. To date, the book has only been included with the VHS release.

VHS release credits
The following additional credits appear on the VHS release after the standard Doctor Who credits, and appear over a still shot of that release's version of the Shada prison floating in space with music exclusive to that release.
 * Presented by - Tom Baker
 * Links Recorded at the Museum of the Moving Image, London.
 * Cameraman - Gerry Ellis
 * Sound - Dave Hill
 * Make-Up - Erika Wareing
 * Lighting - Ian Dow
 * Krarg Supplied by - Lorne Martin
 * Incidental Music - Keff McCulloch
 * Special Sound - Dick Mills
 * Sound Dubbing - Gemini Audio
 * Researcher - Ross McGinley
 * Video Tape Editor - Simon Ashcroft
 * Additonal Effects - Ace Editing
 * Producer - John Nathan-Turner

DVD and Blu-ray releases
On 7 January, 2013, Shada was released in the DVD boxset, The Legacy Collection. It was released with the 90 minute documentary, More Than Thirty Years in the TARDIS. It was re-released again in 2017 featuring the animated reconstructions for both DVD and Blu-ray.

Webcast version
BBC commissioned Big Finish Productions to write and record a new version as part of Doctor Who's 40th anniversary. It was animated with a limited Flash animation and released on the BBC's website. This version was revised to feature Paul McGann's Eighth Doctor, along with Lalla Ward and John Leeson voicing their original characters. This version also incorporated other then-current elements of Big Finish continuity, such as Romana becoming President of Gallifrey after parting ways with the Doctor.

An extended audio version of the webcast was later released on CD by Big Finish. The original version of the webcast was also included as a DVD-ROM bonus item in the 2013 Legacy Collection DVD release of Shada.

Novelisations

 * No official novelisation of Shada was ever published by Target Books, as they were unable to come to an agreement with Douglas Adams that would have allowed him, or another author, to adapt the story. However, the short scene filmed for Shada subsequently used in The Five Doctors was novelised by Terrance Dicks for that story's adaptation.
 * Douglas Adams reused some of the elements of Shada in, notably the character of Professor Chronotis, his time-travelling apartment, and St. Cedd's college. Elements of the Doctor Who mythos not created by Adams (such as the identification of Chronotis' species as Time Lord or his time and space machine as a TARDIS) did not appear in this novel.
 * In early 2011, BBC Books announced that Gareth Roberts had been commissioned to write an official novelisation of Shada, for release in hardback in March 2012. Its publication follows an the agreement with the estate of Douglas Adams and was the first novelisation of a regular TV Doctor Who story since 1994. This novelisation was also released as an audiobook read by Lalla Ward and John Leeson. An ebook was also released on the Amazon Kindle store.