Doctor Who (1963–1989)
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The Ribos Operation: Part Four 

The Doctor returns to the city to keep an eye on the Graff, leaving Romana, K9 and Garron to search for Unstoffe and the first segment.However, Garron double crosses them and steals the tracer.


Robert Holmes (by)




Episode complete credited cast:
Tom Baker ... Doctor Who
Mary Tamm ... Romana
Iain Cuthbertson ... Garron
Nigel Plaskitt Nigel Plaskitt ... Unstoffe
Paul Seed Paul Seed ... Graff Vynda-K
Robert Keegan Robert Keegan ... Sholakh
Timothy Bateson ... Binro
Ann Tirard ... The Seeker
Prentis Hancock ... Captain
Oliver Maguire Oliver Maguire ... Shrieve
John Leeson ... K9 (voice)


The Doctor returns to the city to keep an eye on the Graff, leaving Romana, K9 and Garron to search for Unstoffe and the first segment.However, Garron double crosses them and steals the tracer.

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Release Date:

23 September 1978 (UK) See more »

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Technical Specs


Sound Mix:




Aspect Ratio:

1.33 : 1
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Did You Know?


In the original script, the Graff did not murder the Seeker but instead sent her back to the Catacombs, whereupon the Captain set off the explosion to seal the caves (killing the Seeker in the process). Believing himself to be the prophecied 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, proclaiming the Graff's final end. See more »

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User Reviews

The Key to Time - Story 1
3 December 2019 | by A_Kind_Of_CineMagicSee all my reviews

Review of all 4 parts:

This 4 part story is the first story in Season 16 and is the start of the first ever full season story arc which is called The Key to Time. That arc involves The Doctor being set a task by the White Guardian to find the Key to Time which is in different parts spread across different locations. He is given a device to locate them and a new assistant who is a female Timelord (Romana, played by Mary Tamm). The aim is to unite the Key and stop it falling into the hands of the villainous Black Guardian.

The Doctor is guided to Ribos, location of the first part of the Key where he discovers shady salesmen trying to sell the planet and an unpleasant military leader trying to buy it.

The story is largely comedic, in keeping with the later Tom Baker seasons (as opposed to the darker, more serious and stronger earlier Tom Baker seasons) but in this case the humour is well written and funny thanks to the great writer Robert Holmes. The two conmen are a very amusing duo with some really nice dialogue. Tom Baker and Mary Tamm are also immediately very amusing together with the sparkling script delivered to perfection by them. K-9 adds some fun asides and the whole story bubbles along entertainingly.

There are more serious aspects. The villains are more serious at times but also rather larger than life. Some lovely scenes occur with the character Binro, who had been declared a heretic for believing the stars were all other suns with other worlds around them. His realisation that he was right and the beautiful dialogue and emotion really adds another dimension to this story.

Even the monster in the catacombs is pretty good for the time and the overall story is strong.

Interesting, humorous and very enjoyable.

My ratings: All 4 episodes - 9/10.

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