Richard Hurndall portrayed the First Doctor, as the character's original actor, William Hartnell, had died since his last appearance on the show ten years previously.
Since Tom Baker decided not to appear in the special, footage from the unfinished serial Shada was used to portray the Fourth Doctor.
An unknown entity uses the Time Scoop to bring several of the previous incarnations of the Doctor; his former companions Susan Foreman, Sarah Jane Smith, and Brigadier Lethbridge-Stewart; and his enemies the Daleks, the Cybermen, a Raston Warrior Robot and a Yeti, from their respective time streams into the Death Zone on Gallifrey.
The Fifth Doctor senses the disruption of his own timeline, and with his own companions Tegan and Turlough, travels to Gallifrey via his TARDIS, also ending up in the Death Zone, unable to travel farther with the TARDIS due to a force field projected by the Tomb of Rassilon, the tower at the centre of the Death Zone.
In the Citadel on Gallifrey, the High Council of Time Lords have also detected the disturbance in the Doctor's timeline and the power drain from the Time Scoop, and Lord President Borusa has the Master summoned, to help rescue the Doctor, offering him a new set of regenerations and a pardon if he succeeds.
The Castellan is found to possess the forbidden Black Scrolls of Rassilon, and dies while attempting to escape an invasive mind probe.
Borusa reveals he seeks to be the President Eternal of Gallifrey and needed the Doctors to disable the force field over the Tomb in order to gain immortality from Rassilon's Ring and rule forever.
Meanwhile, the Master meets the First Doctor and Tegan and rids himself of the Cybermen by letting them fall victim to the Death Zone's traps, before killing the Cyberleader with one of his subordinates' guns.
Chancellor Flavia arrives via transmat, with the Chancellery Guard, and, after learning of Borusa's fate, declares that the Doctor is now Lord President, a position he cannot refuse.
Nathan-Turner's first choice of director for the story was Waris Hussein, who had directed the first-ever Doctor Who serial, An Unearthly Child, in 1963.
The episode breaks were, respectively, Sarah falling down the slope, the Cybermen placing their bomb outside the TARDIS while Susan and Turlough watch, and the Master appearing behind the First Doctor and Tegan while in the Dark Tower.
This is the only programme from the classic series of Doctor Who for which all recorded and filmed material, including alternative and unused takes, fluffed scenes and so forth, still exists in broadcast-quality format.
[13] When Frazer Hines, Jamie's actor, proved unavailable for more than a cameo appearance the script had to be altered, pairing the Second Doctor with Victoria Waterfield.
This was revised again when Deborah Watling, Victoria's actress, became unavailable and Baker decided not to appear, resulting in the pairings of the First Doctor with Susan, the Second with the Brigadier, the Third with Sarah Jane Smith, and the Fifth with Tegan and Turlough.
Deborah Watling was unable to make the recording dates but Frazer Hines was able to free himself up for a day's shooting, so Jamie was written in instead.
[14] In April 2013, Carole Ann Ford revealed the producer had initially insisted that Susan not refer to the Doctor as her grandfather: "You will not believe why.
The broadcast in the United Kingdom was delayed two days so it could coincide with the BBC's Children in Need charity night, with an outro in character by Peter Davison.
[17] Paul Cornell, Martin Day and Keith Topping wrote of the special in The Discontinuity Guide (1995), "A fine anniversary tale, although don't analyse the plot too closely as it's largely a collection of set pieces without a great deal of substance.
"[18] In The Television Companion (1998), David J. Howe and Stephen James Walker stated that "The Five Doctors" "is not as bad as it could have been ... [but] the story fairly groans at the seams with the inclusion of so many 'old favourites'."
[19] In 2012, Patrick Mulkern of Radio Times found the serial fun and made with a lot of love, though he noted the Third Doctor and Sarah Jane fared less well than some of the others.
He also called it "Anthony Ainley's most effective outing" and praised the efficient scripting and other aspects of production aside from Moffatt's "sedate" direction.
[20] DVD Talk's Stuart Galbraith gave the story four out of five stars, finding Hurndall's performance as the First Doctor "the show's biggest, most delightful surprise".
[21] Writing for io9, Alasdair Wilkins said that the special was "far from perfect" and "a big, silly adventure", but worked "much better if you can selectively switch your brain off".
[22] Digital Spy's Morgan Jeffery gave the story three out of five stars, writing that it was "not the show's finest hour" but adding that it was "fun if enjoyed in the right frame of mind.