New to Doctor Who or returning after a break? Check out our guides designed to help you find your way!



The Ribos Operation was the first serial of season 16 of Doctor Who. It began the season-long quest to find the legendary Key to Time. All four parts of The Ribos Operation ran over the allocated time, so a significant amount of material was cut for the broadcast version. Some of this material was reinstated in Ian Marter's novelisation.

There was much debate as to whether K9 should return after the problems the prop had caused in season 15. The character was popular with younger audiences so, with the assurance that the new prop was more efficient, Graham Williams approved the introduction of K9 Mark II.

Tom Baker's lip was cut when he was bitten by a dog, which meant he had a visible sticking plaster on his face in the publicity stills for this story. The scar from the injury remained visible in much of this and subsequent stories.

The Ribos Operation was notable for seeing a number of debut appearances. It was the first serial to feature Mary Tamm as companion Romana I and was also the first to properly feature K9 Mark II. The White Guardian also made his debut. He was not seen again until Enlightenment, though his voice (provided by Gerald Cross) was heard in The Stones of Blood.


The Doctor is summoned by the mysterious and powerful White Guardian, and sent on a quest to find the six segments of the Key to Time, which, once assembled, will restore balance to the Universe. Joining the Doctor and K9 is the smart and sassy Romana, a Time Lord fresh from the Academy.

Landing on the wintry planet of Ribos to locate the first segment, the TARDIS crew quickly find themselves embroiled in a little local trouble with a pair of con men and an unstable warlord...


Part one[]

Ribos part1

The Doctor meets the White Guardian.

Using a dog whistle to awaken K9, the Doctor begins busily planning a holiday to Halergan 3. Suddenly, the TARDIS goes dark, and a mysterious voice summons him from outside. The White Guardian asks the Doctor to complete a task for him — to find the six segments of the Key to Time, an immensely powerful cube which maintains the equilibrium of time. The segments are hidden throughout the cosmos, though they can be found with a locator. Before the Doctor embarks on the quest, he is warned that there is a dangerous Black Guardian who also covets the Key.

Returning to the TARDIS, the Doctor tells K9 that their holiday is off and finds that he has been assigned a new assistant, a Time Lord named Romanadvoratrelundar, whom the Doctor calls "Romana". As a new recruit from the Time Lord Academy on Gallifrey, Romana is inexperienced, but she believes herself just as capable as the Doctor, who would rather work alone. The Doctor, though incensed to find that there is now a hole in his console, inserts the locator in the hole and sees that the first segment is presently on Cyrrhenis Minima... at least, it is for a moment, before the coordinates change to new ones: Ribos, 116 parsecs away.

Meanwhile, on Ribos, Garron and Unstoffe are atop a parapet of the castle of Shur that houses the planet's crown jewels. As guards in the vault extinguish the lights and secure the room, Unstoffe drops a chunk of drugged meat into the chamber, then lowers a ladder. Unstoffe reluctantly climbs down, stepping off the ladder next to the sleeping Shrivenzale. Working quickly but quietly, he cuts a hole in the glass case housing the valuable jewels. Then, rather than steal anything, he places in a large piece of jethrik, a precious blue stone and the rarest and most valued mineral in the galaxy.

Garron leaves to meet the Graff Vynda-K, an exiled tyrant. Shortly after they make their introductions and leave, the Doctor's TARDIS materialises and the two Time Lords emerge. As the Doctor is instructing Romana on the value of always expecting the unexpected, he is unexpectedly caught in a net.

The Graff is impressed by the planet's supposed quantity of jethrik. Garron uses a bug in the Graff's chamber to monitor his conversation with Sholakh, the Graff's loyal aide, but he is interrupted by the Doctor and Romana in the passageway. He effects the manner of a watchman to make his escape, calling out, "Four o'clock and all's well!" as he walks away. But the Doctor is puzzled by the fact that he does it with a Somerset accent.

The locator points the Doctor and Romana to the chamber containing the jethrik and the Crown Jewels of Ribos. As the Doctor tries to open the locks to retrieve the segment, Unstoffe joins one of the guards atop the tower and gives him a drink, which conveniently knocks him out. Unstoffe blows the guard's horn, and the guards below lower the door to the Shrivenzale's chamber — trapping the Doctor and Romana with the waking beast...

Part two[]

The guards operating the door notice an obstruction to the door - Romana is pinned beneath it - and, fearing harm to the Shrivenzale, lift it up again. The Doctor and Romana escape back into the main room and the door is soon closed again, keeping the Shrivenzale at bay in its chamber. The Doctor and Romana hide when guards enter the room, followed by Garron, who asks for a substantial sum of money to be kept there for protection. The Doctor is concerned he may also be after the segment.

The money will, of course, be the Graff Vynda-K's deposit for his purchase of the planet, which he intends to use as a base to build an army and a battle fleet. The Graff is intrigued when Unstoffe, pretending to be a native of Ribos, concocts a tale about a lost mine containing an excess of jethrik. He sends Sholakh for his money, then discovers the bug planted in his chamber. He realises that Garron is trying to con him.

Later, Unstoffe distracts the Shrivenzale, recovers their piece of jethrik, and takes the money from the safe. By now, the Doctor has realised that the piece of jethrik is the segment. He also tries to take it, but the guards are alerted, prompting him to escape using Unstoffe's route while Unstoffe bolts through the door with the jethrik. However, an angry Graff, who intends to kill them for deceiving him, intercepts the Doctor, Romana and Garron. He orders their execution on the spot...

Part three[]

Distracted momentarily by the Doctor and advised by Sholakh to remember the money stolen, the Graff instead takes Garron prisoner with his presumed accomplices, the Doctor and Romana. The Graff confronts the Shrieve captain to see what is being done. Noticing the jethrik is gone as well, he discovers the "scringestone" tale is a lie. Meanwhile, Sholakh discovers that Garron has an accomplice when his communicator begins beeping. After Sholakh leaves, the Doctor uses his dog whistle to summon K9.

Unstoffe hides with Binro, a homeless outcast who believes that Ribos is a planet orbiting a star, which Unstoffe confirms to be true. The Ribos guards summon the Seeker, who locates Unstoffe's hideout. The guards prepare a pre-dawn raid. The Graff has other plans and orders Sholakh to rally his men, go in to massacre all the Ribosians, take the jethrik and leave.

Using the listening device in the Graff's room, Garron warns Unstoffe about the Graff. While the Seeker and the Graff are in the concourse, Binro, thankful for Unstoffe's encouragement, leads him to the labyrinthine catacombs under the city. K9 helps the Doctor, Romana and Garron escape from the Graff's quarters.

The Graff and his men enter the catacombs without the Ribos guards, who fear the place as the home of the Ice Gods. Binro and Unstoffe don't fear the Ice Gods, knowing they are mythical, but they do fear the nest of Shrivenzales they hear in the distance. The Doctor's group is not far behind them, but they are forced to hide when the Graff's party comes upon them. Unfortunately, the Doctor gives away their presence when a skull falls to the floor...

Part four[]

The noise of the skull also draws the attention of a Shrivenzale, scattering the Graff's men. Reflecting on the difficulty of finding their quarry, Sholakh advises the Graff to use the Seeker as her earlier information was accurate.

The Doctor sends the rest of his group ahead and doubles back to the city. Farther down in the catacombs, Unstoffe and Binro split up, the latter also doubling back to see if he can determine Garron's fate. Unstoffe gives Binro his communicator to demonstrate to Garron that it isn't a trick of any sort. At the entrance to the catacombs, the impatient Graff kills one of the guardsmen in front of the Shrieve captain to convey his displeasure with being made to wait for the Seeker. After witnessing this display of ruthlessness from a hiding place, the Doctor returns to the Graff's chambers. There, he stands over the fallen soldier whom K9 had earlier incapacitated.

Garron steals the locator from Romana and heads off to locate the jethrik and Unstoffe, in that order. The Seeker, meanwhile, foresees that if they enter the catacombs, "all but one" of the party will die. Nevertheless, she leads the Graff and his men into the catacombs. They encounter Binro, whom they mistake for a grave robber. Seeing he has Unstoffe's communicator, they take him with them to assist in finding Unstoffe. They proceed deeper. As they head off, the tail of a scarf peeks out from the robe of the last guard in line...

The Graff corners Unstoffe and Garron. Binro runs to try to warn them and is shot dead. He dies content in the knowledge that he was right about his measurements of the stars. Unstoffe, upset, moves towards the Graff and is wounded. Garron bluffs the Graff by claiming the Doctor and Romana are interstellar agents, who have stumbled across the Graff's crimes while they were arresting Garron. This only serves to enrage the Graff further. Unnoticed by all, in all this activity, is one of the Graff's guards, blowing a dog whistle. Adding to the chaos, a shrivenzale draws near.

The Ribos guards use a cannon to destroy the entrance to the catacombs, causing the ceiling to collapse on the Graff's men. The collapse traps Unstoffe and Garron, but they are freed by K9. Romana reclaims the tracer that Garron stole. The Graff notices that Sholak is trapped and tries to save him, but it is too late. With the money and the piece of Jethrik, the Graff recalls the Seeker's prophecy that all but one of his group will die. He kills the Seeker to make sure that he will be the only one who survives. His last surviving guard, actually the Doctor in disguise, moves towards her as she is killed, but the Graff announces that his guard will receive a more honourable death. He gives the Doctor an explosive to kill himself with.

First segment

"Only five more to go."

The Graff walks off into the maze yelling for Sholak when there is an explosion. The Doctor switched the explosive for the Jethrik.

After leaving the catacombs, Garron and Unstoffe are free to commandeer the Graff's deserted ship but Garron asks the Doctor whether he may hold the Jethrik one last time. The Doctor lets him and he secretly slips it into his pocket but then seemingly gives it back to the Doctor. He, Romana and K9 then depart in the TARDIS. Unstoffe is disappointed that they've lost the Jethrik but Garron smugly tells him that he switched the Jethrik for an ordinary stone. He holds his hand up only to discover he's holding the ordinary stone; the Doctor switched it back! Garron is outraged at this and he and Unstoffe leave. In the TARDIS, Romana converts the Jethrik into the first piece of the Key to Time. The Doctor then looks at the segment and comments, "Only five more to go."


Uncredited cast[]


Uncredited crew[]



The Doctor[]

  • The Doctor claims to have been trained in sleight of hand by John Nevil Maskelyne, a well-known stage magician from the late 19th century.
  • Romana catches the Doctor lying, or being confused, about his own age: 756 instead of 759.


  • Opek is a currency accepted on Ribos.






  • By its inhabitants, Ribos is believed a battlefield between Ice Gods and Sun Gods. This would cause the turnover of the seasons - icetime and suntime.

Science and technology[]

  • The Doctor and Romana express interstellar distances in parsecs.
  • Ribos hasn't invented the telescope yet.
  • Garron says he wants to contact his (non-existent) clients by hyper-cable.
  • The explosive thermite is used to seal the catacombs and is the cause of the death of the Graff.


Story notes[]

  • This story marks the beginning of the quest for the Key to Time. All stories in season 16 were linked to this theme. This was the first time a story arc encompassed an entire season (all of the stories of season 8 were related to the Master, but they were separate standalone stories).
  • Working titles for this story include Operation, The Galactic Conman[1] and The Ribos File.[2]
  • This story was the last season opener to introduce a new companion until Rose in 2005; although Lalla Ward takes over as Romana in the following series-opener, she is still the same character. All of the following companions were introduced midway through, or at the end, of a series.
  • The Radio Times programme listing for part one was accompanied by a black-and-white head-and-shoulders photograph of Romana and the Doctor, with the accompanying caption "Dr. Who's new assistant — Mary Tamm as Romana joins Tom Baker: 5.45" (original published text); while that for part two was accompanied by a black-and-white publicity shot of Romana, with the accompanying caption "Romanadvoratrelundar (Romana for short) the new-graduate Time Lord. Mary Tamm in Dr. Who: 6.20". (original published text)
  • The Key to Time prop was created by visual effects designer Dave Havard.
  • Originally, the shortened form of Romanadvoratrelundar's name was to be "Romy," as noted on the Special Edition DVD Info Text.
  • On the night before the last day of recording The Ribos Operation, Tom Baker was bitten on the left side of his upper lip by a Jack Russell dog belonging to Paul Seed, who played the Graff Vynda-K. Publicity photographs from late April show Baker with a sticking plaster on his lip. The wound had to be concealed with makeup, much to the actor's discomfort, and where possible George Spenton-Foster changed his camera angles to keep the other side of Baker's face forward. The scar was quite noticeable on-screen throughout most of this season and the next.
  • This story includes a rare instance of the Doctor acting directly to kill a human(oid) enemy when the Doctor does a switch and leaves the murderous Graff holding his own explosive.
  • Elisabeth Sladen, who as Sarah Jane Smith was last seen in The Hand of Fear, was approached to return to the series as a replacement for Leela (who had left in The Invasion of Time). When Sladen declined the offer, the character of Romana was created instead.
  • K9 does not appear in part two.
  • The original credits list the White Guardian as simply "The Guardian." This may be a hint at a suspicion the Doctor voices at the climax of The Armageddon Factor, that he and Romana have all along been working for the Black Guardian disguised as his more benevolent counterpart. However, the original intent of Graham Williams and Anthony Read was that the Guardian seen in this story was indeed the White Guardian. (INFO: The Ribos Operation)
  • From this story until The Horns of Nimon, the Doctor will wear an extra long scarf, which is the remaining portion of original scarf and the stunt scarf sewn together.
  • Garron was originally Australian, hence the reference to his fraudulent sale of the Sydney Opera House. He became a Londoner when Iain Cuthbertson was cast in the role.
  • The Seeker was originally a man.
  • The sets were left over from the BBC's adaptation of Anna Karenina.
  • The script originally called for the Doctor to be in awe of the White Guardian. However, Tom Baker insisted on playing it mockingly while trying not to laugh at how serious it all was.
  • Initially, the jethrik was important because it was actually a source of incredible energy which could power a fleet of spaceships.
  • Ribos was patterned after medieval Russia, its name being an anagram of the common Russian name “Boris”. The currency of Ribos, the opek, was a reference to both the Russian kopec (one-hundredth of a ruble) and the Organisation of Petroleum-Exporting Countries, better known by its acronym OPEC.
  • The scene with the White Guardian was written by Anthony Read and Graham Williams.
  • It was Anthony Read's idea for the Jethrik to be the first segment of the Key to Time.
  • During production, George Spenton-Foster quickly had to contend with a demarcation dispute amongst the crew, arising from a disagreement over who was responsible for lighting the torches which decorated many of the Ribos sets.
  • Tom Baker took exception to Romana's bright white dress, which he found distracting. Although it was intended that she would always be seen in white in to reflect the notion of her as an “ice queen”, these plans were hastily dropped.
  • George Spenton-Foster had planned to erect large coloured screens so that chroma key could be used to enlarge the scale of sets such as the White Guardian's limbo, and magnify the size of the Shrivenzale in the Catacombs. However, the floor technicians could not agree on who should operate the screens, and so the effect had to be largely abandoned.
  • Originally, the Graff did not murder the Seeker himself but instead sent her back to the Catacombs, whereupon the Captain set off the explosion to seal the caves and killed the Seeker in the process. Believing himself to be the prophesied survivor, the Graff -- insane and hallucinating about past campaigns -- then took an ammunition pouch from a supposedly dead guard. The Doctor would reveal himself at this stage while an explosion detonated, heralding the Graff's demise.
  • Mary Tamm and Louise Jameson were classmates at RADA. In advance of rehearsals, Jameson had warned Tamm of her difficult relationship with Tom Baker. As a result, the new lead actress made certain to stand her ground when Baker behaved rudely towards her. This earned her co-star's respect, and they would get along well with each other from that point forward.
  • Paul Seed had previously starred in the short-lived series The Double Dealers, which Graham Williams script-edited.
  • Romana's white coat would later be worn be Jacqueline Pearce in some episodes of Blake's 7.


  • Part one - 8.3 million viewers
  • Part two - 8.1 million viewers
  • Part three - 7.9 million viewers
  • Part four - 8.2 million viewers

Filming locations[]

Myths and rumours[]

  • The previous story, The Invasion of Time, introduced a female Time Lord named Rodan, played by Hilary Ryan. A rumour/myth related to this serial is that Romana was originally to have been Rodan, but Ryan was unavailable so a new character was created.
  • Conversely, there is a related misconception that this story marks the first appearance of a named female Time Lord (Susan Foreman notwithstanding) and that female Time Lords have long, complex names. The appearance of Rodan in the previous story contradicts this myth (although it's possible Rodan is a shortened form of that name, just like Romana).

Production errors[]

If you'd like to talk about narrative problems with this story — like plot holes and things that seem to contradict other stories — please go to this episode's discontinuity discussion.
  • The Doctor's memory of recent events was wiped towards the end of The Invasion of Time, following his use of the De-mat Gun, so he should have no memory of the Sontarans' attempted invasion of Gallifrey, which he mentions in part one. (However, it could be argued that the Doctor's memory was restored when the TARDIS entered the White Guardian's domain. Also, no-one else in the story lost their memory so it's possible someone else told him offscreen.)
  • Garron's communicator falls off his wrist as he and Unstoffe are lifting off the metal plate at the top of the shaft in part one.
  • Romana notably finds Ribos cold and has to put on a coat to stay warm. However the Doctor does not feel the cold (which has been established in previous adventures) and, given that the two of them are the same species, it is logical to assume that she would not feel the cold either. (However there is no reason to assume every member of a species feels the same way, much as humans from warm backgrounds may struggle with the cold more than those from cold backgrounds.)
  • The Captain examines the door leading to the shrivenzale and then turns to his right which means he looks directly at where Romana is hiding yet he does not see her.
  • When the Captain is talking to Garron in the treasure room he is looking at him but when the camera changes angles, he is now looking away from him.
  • When K9 goes into the hole at the end of part three, he enters nose first. But when he emerges in part four, he has turned around.
  • When the jethrik stone is being converted into the segment, Romana's grip on the tracer changes.
  • When the Doctor and Romana exit the TARDIS in part one, the door is left open. But when K9 is later shown exiting the TARDIS in part three, the door is closed.


Home video and audio releases[]

DVD releases[]

Special Features (2007/2009 version)[]


The Key to Time boxed set covers[]

Doctor Who DVD Files[]

It was released as issue 107 of Doctor Who DVD Files.

Video release[]

  • This story was released on VHS in April 1995 in PAL and NTSC formats, with the UK version featuring cover art by Colin Howard and spine art by Andrew Skilleter.

Digital releases[]

  • The story is available for streaming through BritBox (Canada and US) as part of Season 16 of Classic Doctor Who.
  • It is also available to download through iTunes.

External links[]