Doctor Who (1963–1989)
4 user 2 critic

The Sontaran Experiment: Part Two 

The Doctor learns that Styre has been experimenting on the Galsec crewmembers to pave the way for a Sontaran invasion of Earth and decides the only way to halt his plans is to challenge him to a duel.


Rodney Bennett

On Disc

at Amazon




Episode complete credited cast:
Tom Baker ... Doctor Who
Elisabeth Sladen ... Sarah Jane Smith
Ian Marter ... Harry Sullivan
Kevin Lindsay Kevin Lindsay ... Styre / The Marshal
Donald Douglas ... Vural
Glyn Jones Glyn Jones ... Krans
Peter Walshe Peter Walshe ... Erak
Peter Rutherford Peter Rutherford ... Roth
Brian Ellis Brian Ellis ... Prisoner


The Doctor learns that Styre has been experimenting on the Galsec crewmembers to pave the way for a Sontaran invasion of Earth and decides the only way to halt his plans is to challenge him to a duel.

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Release Date:

1 March 1975 (UK) See more »

Company Credits

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Technical Specs


Sound Mix:




Aspect Ratio:

1.33 : 1
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Did You Know?


This episode was watched by 10.5 million viewers on its original transmission. See more »


When The Doctor leaps onto Styre from behind, the machete goes flying out of Styre's hands, obviously to land fairly far away, but in the next shot it's right beside Styre's hand as he gets up. See more »

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User Reviews

Experiment in more ways than one with very good results.
18 November 2014 | by A_Kind_Of_CineMagicSee all my reviews

Review of both episodes:

It was an experiment to have the first two-part story for many years and to film the entire story on location in an outdoor setting (Dartmoor National Park). These experiments work well as the location work is very good and the two part story is very neat with no waste or time for boredom. On the other hand this never quite manages to go beyond an excellent bit of entertainment to reach 10/10 classic status.

The story follows on from The Ark in Space. The Doctor, Sarah and Harry travel via Transmat to Earth from space station Nerva 10,000 years in the future. There they find a tiny group of humans some of whom have been captured and tortured by a mysterious alien that turns out to be a Sontaran. The experiments are being done on the humans to find their weaknesses in preparation for a Sontaran attack on humanity.

Some criticisms I have read are not deserved in my view as for instance I have seen it said that it does not make sense the Sontarans are wasting time testing humans when there are very few surviving on Earth but it is clearly suggested in The Ark in Space that the humans on Nerva are the chosen people to take humanity forward but not the only humans left. It is clearly said in that previous story and in this one that there are other human colonies and it is also suggested that the Sontarans plan to wage war on the humans elsewhere not just those living on Earth. So this all makes more sense than some critics claim. It does seem a slightly inefficient and unnecessary strategy but it is credible enough.

This is an entertaining story with a welcome return for Sontarans and good performances. It is gritty and yet fun. It is not a 10/10 classic but is very good and neatly presented as a tight two parter.

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