The One Doctor was the twenty-seventh story in Big Finish's monthly range. It was written by Gareth Roberts and Clayton Hickman and featured Colin Baker as the Sixth Doctor and Bonnie Langford as Melanie Bush.
This audio was released in December 2001 and was considered Big Finish's "Christmas release". It has a notably comic slant to the story. It is the first of two early Christmas releases in the Main Range, the second being AUDIO: Bang-Bang-a-Boom!. Both stories feature Mel.
So it's lucky that the Doctor, that famous traveller in time and space, is in the area, and that he, along with his pretty young assistant, Sally-Anne, manages to defeat the deadly creatures and save the day.
But now it looks as though the Doctor's luck has run out.
Who is the mysterious, curly-haired stranger, intent on causing trouble? What role does the feisty redhead Melanie play in his scheme? And what have they to do with the sinister alien cylinder approaching Generios?
One thing is certain: for the Doctor and Sally-Anne, there's deadly danger ahead...
to be added
- The Doctor - Colin Baker
- Melanie Bush - Bonnie Langford
- Banto Zame - Christopher Biggins
- Sally-Anne Stubbins - Clare Buckfield
- Cylinder / The Jelloid - Matt Lucas
- Councillor Potikol / Assembler 2 - Stephen Fewell
- Citizen Sokkery / Mentos - Nicholas Pegg
- The Questioner / Queen Elizabeth - Jane Goddard
- Assembler 1 - Adam Buxton
- Guards - Mark Wright & Alistair Lock
- The Cylinder calls the Doctor Johann Schimdt, Doktor von Wer, Ka Faraq Gatri, Theta Sigma and Snail.
- The Questioner poses a question to Mentos about the Masterbakers of Barastabon.
- Mentos answered that Gentex Nondrian was reported to have originated the phrase "you can take a Pescaton to water but you can't make him sing" to a question posed by the Questioner.
- Thinkum the Lesser invented the Sponecatcher
- In June 1975, the Doctor based himself in 35 Jefferson Road, Woking during an invasion by Cybermen.
- Mel as a girl lived in a large house in Pease Pottage, about seven miles from town.
- The Spraxis Jelloids are large, single-celled organisms who can live in excess of fifty million years.
- The Sinister Sponges worship the Loofah of Life.
- A Spaag from Vishtek 3 ate Sally-Anne's Aunty Sue.
- The Quarks are mentioned by Banto.
- The young of the Pomtemrays are called the Letvilles.
- Banto Zame is from the planet Osphogus, which was terraformed five thousand years before the time of the story.
- The Jelloid is expecting a home entertainment system from the planet Bendalos. The depot for said entertainment system is on Sirrinus Traxia.
- Abydos is located in the Rim Worlds; nothing much is out there. Banto wanted to buy it.
- The STARDIS, Banto and Sally-Anne's mock TARDIS, is shaped like a portaloo.
- Banto uses a psychic screwdriver, equivalent to the Doctor's sonic screwdriver, to seemingly defeat the Skelloids.
- The Cylinder projects its transmission over Generios 1 with a Multi-Phase Corpolectic Sound Wave.
- At the start of this adventure the Doctor is indulging in his megalomaniacal side by playing Monopoly.
Three Great Treasures of Generios
- UNIT ZX419, also known as the Shelves of Infinity, are infinite and therefore impossible to put up.
- The quiz show The Feeblest Contestant has been going on for 33,000 years.
- This is the first of Big Finish Productions' "Christmas releases" stories. They are a bit more light-hearted than other releases. The following year's Christmas release was Bang-Bang-a-Boom!, a story again parodying popular media-culture. In years following Bang-Bang-a-Boom!'s release, Big Finish offered subscriber only special releases, although those tended to cover all genres rather than the lighter-toned style that this story and Bang-Bang-a-Boom! use.
- The title of this story is a reference towards the tendencies for Multi-Doctor stories to feature the number of Doctors in the story within the title (including such stories as The Three Doctors, The Five Doctors, The Two Doctors, The Eight Doctors, The Four Doctors, Four Doctors). In this case, the title jokingly hints that the extra Doctor included within the story will be revealed to be a fake, meaning that the Sixth Doctor is the one Doctor within the story.
- The third episode features the alternative Delaware version of the Doctor Who theme tune, a nod to the overseas print of Carnival of Monsters.
- This audio drama was recorded on 28 and 29 April 2001 at The Moat Studios.
- The second CD contains a bonus track containing two scenes. In the first of these, the Doctor and Mel attempt to use the Time-Space Visualiser to watch The Queen's Speech, but accidentally tune in to Elizabeth I. In the second, the Questioner asks Mentos a number of questions from throughout time and space. Both scenes end with the characters wishing Merry Christmas "to all of you at home". (TV: The Daleks' Master Plan) The bonus track was posted on Big Finish's official Soundcloud in December 2012. 
- Jim Mortimore and Jane Elphinstone's score to this story, alongside the score to Bloodtide and Project: Twilight, was released on the CD Music from the Sixth Doctor Audio Adventures.
- This story is set between The Trial of a Time Lord and Time and the Rani.
- This story was originally released on CD. It is now available as a download only.
- Mentos asks the Doctor if he's going to use one of those "fox the computer conundrums...the last thing I said was false and all that". This alludes to a popular means of defeating misguided or evil computers in Star Trek but also references TV: The Green Death. The Eighth Doctor would experience a similar failure in using such questions on the Brain in PROSE: The Space Age, but simply muses that at least it shows people are building the computers properly. TV: The Dæmons also features a Dæmon being destroyed in a similar manner, although they are not machine beings.
- The names that the Cylinder calls the Doctor hail from specific stories: Johann Schmidt (AUDIO: Colditz, Klein's Story, Storm Warning; PROSE: Timewyrm: Exodus, The Shadow in the Glass), Doktor von Wer (TV: The Highlanders), Ka Faraq Gatri (PROSE: Remembrance of the Daleks, PROSE: Timewyrm: Revelation) Theta Sigma (TV: The Armageddon Factor, TV: The Happiness Patrol) and Snail (PROSE: Lungbarrow).
- The Doctor claims that he has very good eyesight in the dark due to drinking so much carrot juice. (Mel would have forced him to drink it.) (TV: Terror of the Vervoids, The Ultimate Foe)
- Mel mentions the fact that she has "the memory of an elephant" is a running gag between herself and the Doctor. (TV: Terror of the Vervoids, Time and the Rani)
- The Sixth Doctor's comment that his hair stands on end in the presence of another self is later mentioned in AUDIO: The Light at the End, when he arrives in a pocket dimension at the same time as the Seventh Doctor.
- Official The One Doctor page at bigfinish.com
- DisContinuity for The One Doctor at Tetrapyriarbus - The DisContinuity Guide