Doctor Who (1963–1989)
9 user 5 critic

The Sea of Death 

On the planet Marinus, the Doctor and his companions are enlisted by Arbitan to seek out the keys to an ancient and powerful machine. Their quest takes them across time and space; will they... See full summary »


John Gorrie


Terry Nation


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Episode cast overview:
William Hartnell ... Dr. Who
William Russell ... Ian Chesterton
Jacqueline Hill ... Barbara Wright
Carole Ann Ford ... Susan Foreman
George Coulouris ... Arbitan
Martin Cort Martin Cort ... Voord
Peter Stenson Peter Stenson ... Voord
Gordon Wales Gordon Wales ... Voord


On the planet Marinus, the Doctor and his companions are enlisted by Arbitan to seek out the keys to an ancient and powerful machine. Their quest takes them across time and space; will they be able to return the keys before Marinus falls under the control of the alien Voord? (Originally broadcast in six parts.) Written by Sarah Hadley

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Did You Know?


This episode was watched by 9.9 million viewers on its original transmission. See more »


When Ian is first inside the pyramid, someone stumbles through the background. See more »


Barbara Wright: Then everything out there is acid. A sea of acid.
See more »


Featured in Girls! Girls! Girls! The 1960s (2009) See more »

User Reviews

The Keys of Marinus
8 July 2008 | by ametaphysicalsharkSee all my reviews

Rather generously credited by some fans as a sprawling and ambitious story that was deliberately varied and took place in numerous different locations for creative purposes. Fact is that the story had to be written as fast as possible and it was decided that making it a collection of largely self-contained episodes would make it easier to write.

Terry Nation was a man with a multitude of fantastic and wonderful ideas but let's face it, with the odd exception here and there, he was never really a polished scriptwriter, mostly producing watchable but unremarkable work that required plenty of editorial work from the script editors. "The Keys of Marinus" starts out as exactly this sort of script, hits a peak with the fabulously thrilling third episode, essentially a retread of pulp adventure serials but done wonderfully well, stays fairly strong in the same vein with the fourth episode then bizarrely turns into an awful combination of the whodunit and courtroom thriller genres, worth seeing only for the Doctor's first and last appearance as a clever lawyer (!), and ends with an episode much like the first two. It sure is sprawling but in this case I'm afraid it's just not a good sort of sprawl.

The story in general doesn't achieve any sort of real flow, partly due to Nation's script but also in part due to the static direction by John Gorrie. Of course one cannot expect fluid and mobile direction and editing from the rather clunky and massive 60's video cameras Who was shot on at this point, but once you see what Warris Hussein did with "An Unearthly Child" you come to expect similar quality from other directors, or at least something somewhere near that level.

"The Keys of Marinus" is wonderful, spectacular fun in places. The whole feel of the planet is sprawling and very different to what you usually find in Doctor Who stories, but the vignette style storytelling doesn't quite work. It's like the Key to Time season (which I'm not too fond of anyway) condensed to six episodes rather than stories. All in all this story is watchable and mostly entertaining, but it is a lesser story than the preceding season one adventures.

Episode 1: 6/10, Episode 2: 6/10, Episode 3: 9/10, Episode 4: 7/10, Episode 5: 4/10, Episode 6: 6/10.

Average: 6.33/10

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Release Date:

11 April 1964 (UK) See more »

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Technical Specs

Sound Mix:


Aspect Ratio:

1.33 : 1
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