The Sixth Doctor (1984-1986)
Season Twenty-One 
(1984) Season Twenty-One (1984): Change, My Dear
Season Twenty-Two (1985) Season Twenty-Two (1985): Instabilities
First appearance of the Rani.
Season Twenty-Three 
(1986) Season Twenty-Three (1986): On Trial
First appearances of Mel, the Valeyard, the Inquisitor and Sabalom Glitz.

Season Twenty-One (1984): Change, My Dear

The Doctor
The Sixth Doctor

Colin Baker played the Doctor from The Caves Of Androzani in March 1984 to The Trial Of A Time Lord in December 1986. He returned for Dimensions In Time in November 1993.

The Story
The Twin 
The Twin Dilemma by Anthony Steven, directed by Peter Moffatt
The Doctor experiences serious regenerative instability, causing him to attack Peri and then decide to live as a hermit on the barren moon of Titan. There he stumbles upon a plot by his old friend, the Time Lord Azmael, who has kidnapped twin mathematical geniuses named Romulus and Remus. Azmael's adopted planet, Joconda, has been taken over by the sluglike Mestor and his Gastropods, forcing the Time Lord to do Mestor's bidding. But even Azmael is unaware of Mestor's true plan -- to destroy Joconda's sun, and thereby scatter Gastropod eggs throughout the galaxy.

Making History

The idea behind the Sixth Doctor was to create a character who, in sharp contrast to his generally more amiable predecessors, would initially be a source of suspicion for the audience. Consequently, the Sixth Doctor would appear to be erratic and untrustworthy -- but, in principle at least, would eventually earn the viewer's faith and respect.

Season Twenty-Two (1985): Instabilities

Companions and Recurring Characters

The Rani was a ruthless Time Lord scientist who turned renegade in order to pursue her emoral experiments.

Kate O'Mara played the Rani in The Mark Of The Rani (February 1985), Time And The Rani (September 1987) and Dimensions In Time (November 1993).

The Rani

The Stories
Attack Of The 
Attack Of The Cybermen by Paula Moore, directed by Matthew Robinson
The TARDIS is commandeered by the mercenary Lytton and a group of Cybermen, who are using another captured time machine to travel back to 1985. There, the Cybermen intend to use Halley's Comet to obliterate the Earth, thus preventing the destruction of their home planet Mondas in 1986 and perverting the course of history. Taken prisoner on Telos, the Doctor and Peri escape and ally themselves with the native Cryons. But in order to stop the Cyber plot, they may have to rely on none other than Lytton, whose motivations remain a mystery to all.
Vengeance On 
Vengeance On Varos by Philip Martin, directed by Ron Jones
When the TARDIS runs out of vital Zyton-7 ore, the Doctor makes an emergency landing on the planet Varos, which is rich in the mineral. Varos is a former penal colony whose residents now derive pleasure purely from the televised tortures which perpetually pass across their screens. The Governor of Varos is engaged in negotiations with the ruthless sluglike businessman Sil, who is trying to cheat the Varosians out of their rightful profit on Zyton-7. It is up to the Doctor and Peri to stop Sil's plans, and break the natives of Varos out of their daily cycle of video nasties.
The Mark Of 
The Rani
The Mark Of The Rani by Pip and Jane Baker, directed by Sarah Hellings
The TARDIS is drawn to Earth during the Luddite Uprisings. There, the Master is once again trying to alter the planet's history, while an evil Time Lord called the Rani is also present, extracting chemicals from the brains of local workers for her own use. As a result of the Rani's experiments, rioting amongst the workers is intensifying, threatening the work of famed engineer George Stephenson. It falls to the Doctor and Peri to foil the uneasy partnership between the two villains and restore Earth's history to its proper course.
The Two 
The Two Doctors by Robert Holmes, directed by Peter Moffatt
The Time Lords send the Second Doctor and Jamie to Space Station Camera, to put an end to temporal experiments being conducted by Dastari, an old friend of the Doctor's. Dastari has genetically augmented a savage Androgum named Chessene, who has forged an alliance with the Sontarans. They kidnap the Doctor and take him to Seville, where they plan to isolate the Rassilon Imprimature: the genetic code which allows Time Lords to travel through the vortex. The Sixth Doctor and Peri rescue Jamie and follow the others to Seville, in a race against time with the Doctor's past and future at stake.
Timelash by Glen McCoy, directed by Pennant Roberts
The Doctor and Peri arrive on Karfel, which is ruled by an enigmatic tyrant known as the Borad who wields the power of a space-time tunnel called the Timelash. Investigating, the Doctor learns that the Timelash connects Karfel to nineteenth-century Scotland, where a young HG Wells becomes embroiled in the Borad's schemes. Meanwhile, the Borad stokes the fires of war with Karfel's neighbours, the Bandrils. He plans to use the conflict to repopulate Karfel with beings such as himself: a hideously mutated cross between a human and a reptilian Morlox. And Peri will be but the first...
Revelation Of 
The Daleks
Revelation Of The Daleks by Eric Saward, directed by Graeme Harper
The Doctor and Peri go to Necros to attend the funeral of an old friend of the Doctor's. There they discover that Davros is posing as the Great Healer of Tranquil Repose, a famed institution where the terminally ill can be placed in suspended animation until a cure for their ailment is found. Davros is experimenting on the comatose bodies to produce a new race of Daleks loyal to himself. To defeat his old foe, the Doctor may have no choice but to ally himself with the original Daleks on Skaro.

Making History

Season Twenty-Two saw something old and something new for Doctor Who as the show returned to its old Saturday evening timeslot but was expanded to forty-five minute episodes rather than the traditional twenty-five minute length. Despite this, things did not fare well for the programme; ratings were down slightly on recent years and there were renewed calls that Doctor Who was becoming too violent. Combined with the general lack of funds at the BBC in the mid-Eighties and a disregard for Doctor Who by certain administrators, this prompted BBC management to put the programme on hiatus until September 1986, resulting in the cancellation of the stories originally planned for Season Twenty-Three. Furthermore, it was made clear that, when it did return, Doctor Who would have to justify its existence, or be removed from the schedules again -- permanently.

Season Twenty-Three (1986): On Trial

Companions and Recurring Characters

The Valeyard was a Time Lord who prosecuted the Doctor at his trial, until he was revealed to be some form of aberrant version of the Doctor from the future.

Michael Jayston played the Valeyard throughout The Trial Of A Time Lord from September to December 1986.

The Valeyard

The Inquisitor was a Time Lord who presided over the Doctor's trial with cold efficiency.

Lynda Bellingham played the Inquisitor throughout The Trial Of A Time Lord from September to December 1986.

The Inquisitor

Sabalom Glitz was an intergalactic mercenary and pirate who sometimes helped and sometimes hindered the Doctor -- but always with his own best interests in mind.

Tony Selby played Glitz on a recurring basis from The Trial Of A Time Lord in September 1986 to Dragonfire in December 1987.

Sabalom Glitz

Melanie Bush, or Mel as she preferred to be called, was a computer programmer from Earth gifted with an eidetic memory.

Bonnie Langford played Mel from The Trial Of A Time Lord in November 1986 to Dragonfire in December 1987. She returned for Dimensions In Time in November 1993.

Mel Bush

The Production Team

In the midst of all the turmoil of Season Twenty-Three, the disagreements which had been brewing for years between John Nathan-Turner and Eric Saward finally came to a head following the death of Robert Holmes, to whom Saward had become quite close. Fed up, Saward quit the programme, forcing Nathan-Turner to assume the dual roles of producer and script editor for the concluding episodes of the season.

The Stories
The Trial Of 
A Time Lord (Segment One)
The Trial Of A Time Lord (Segment One) by Robert Holmes, directed by Nicholas Mallett
An amnesiac Doctor is put on trial for his life by the Time Lords and their prosecutor, the Valeyard, who uses the Matrix to show the court the Doctor's recent past. The TARDIS arrives on Ravolox, a planet in the far future supposedly ravaged by a solar flare. In fact, it is perfectly habitable and home to the warlike Tribe of the Free, led by Queen Katryca. The Doctor and Peri soon discover that Ravolox is actually Earth, having been somehow moved light years across space, and that a second race of people lives underground, governed by the robot Drathro. They also meet conmen Glitz and Dibber, who have come to steal Drathro's secrets. But Drathro is dying, and his passing will set into motion a chain of events which will tear Ravolox apart.
The Trial Of 
A Time Lord (Segment Two)
The Trial Of A Time Lord (Segment Two) by Philip Martin, directed by Ron Jones
At the Doctor's trial, the Valeyard presents the Doctor and Peri's most recent adventure. The dying words of a Thordon warlord send the pair to Thoros-Beta, home of the Mentors -- including their old foe, Sil. The Mentor leader, Kiv, has had his intelligence enhanced by the human geneticist Crozier, but now his brain is outgrowing his skull. Crozier sets his eyes on Peri as the new host for Kiv's brain. But when the Doctor appears to turn evil under the effects of one of Crozier's devices, it is left to the berserk warlord King Yrcanos to save his companion.
The Trial 
Of A Time Lord (Segment Three)
The Trial Of A Time Lord (Segment Three) by Pip and Jane Baker, directed by Chris Clough
As evidence for the defense at his trial, the Doctor presents an adventure from his future when he is travelling with a computer programmer named Mel. Answering a mysterious distress call from the space liner Hyperion III, they find that the passengers aboard include unscrupulous scientists, secret agents, saboteurs, thieves... and a murderer. And lurking in the shadows are the Vervoids, the product of sinister botanical experiments, who will stop at nothing to destroy all non-plant life.
The Trial 
Of A Time Lord (Segment Four)
The Trial Of A Time Lord (Segment Four) by Robert Holmes and Pip and Jane Baker, directed by Chris Clough
Appearing from within the Matrix, the Master reveals that the Doctor's trial is part of a conspiracy by the corrupt High Council, who ravaged the Earth and renamed it Ravolox to hide the theft of Matrix secrets. Furthermore, the Valeyard is actually the distillation of the Doctor's evil side between his twelfth and final regeneration. Brought to the trial by the Master, Mel helps the Doctor pursue the Valeyard into the Matrix, where they discover that he is plotting to destroy the High Council. However, the Master has also summoned Glitz as part of his own bid for power.
At the conclusion of the trial, it is revealed that Peri has elected to wed King Yrcanos. Mel travels on with the Doctor.

Making History

When Doctor Who finally returned from its hiatus, restored to standard twenty-five minute episodes, John Nathan-Turner was given explicit orders to tidy the show up or see it cancelled. Consequently, the Trial concept was formulated to parallel Doctor Who's own plight. Ratings after the hiatus were not good, however, amounting to even less than what Season Twenty-Two had attracted. Blaming Colin Baker's portrayal of the Doctor, BBC management fired the actor at the season's conclusion, but decided to renew Doctor Who for one more year. The programme was not out of hot water yet by any means...