Aired 22 February – 1 March 1975

‘The Sontaran Experiment’ sees the return of the titular Sontaran race for the first time since the foe’s debut in ‘The Time Warrior’ as the Doctor and his companions transmat down to anow-healed Earth from Space Station Nerva.’ More notable, though, is that ‘The Sontaran Experiment’ is the first Doctor Who story to be shot entirely on location with no studio sets in what is the first two-part story since the Hartnell era, showcasing the extreme versatility of the programme with little padding.

The premise of ‘The Sontaran Experiment’ is simple enough with a single Sontaran, Styre, assessing the strengths of GalSec spacemen in order to determine the best path for a successfull Sontaran invasion of Earth. Yet while the story is, by design, rather straightforward, it achieves a great deal in highlighting the new Doctor as well as the clear direction in which the new behind-the-scenes staff wants to go. Although Sladen and Marter are pushed more to the background as Sarah Jane and Harry, respectively, since there’s no possible way to thoroughly handle all three leads and tell an engaging story in such a limited time, both still give incredibly strong performances in their allotted scenes. Unquestionably, though the new Fourth Doctor is the highlight, and Tom Baker is consistently excellent as he alternates between facetiousness and improvisation and fury and scheming.

Philip Hinchliffe and Robert Holmes instantly made a mark with the inclusion of more horrific concepts and events in ‘The Ark in Space,’ and that trend does continue somewhat in ‘The Sontaran Experiment’ even with the race that is in itself a parody of the worst military bravado. Whereas Linx of ‘The Time Warrior’ simply wanted to get back to the war against the Rutans, Styre cruelly tortures his captives in order to determine how much pain and anguish the average human can take, a wholly more unsettling prospect. While again the budget may not allow the concepts to be fully realised, the ideas themselves are superb, and seeing and hearing about burns, starvation, and drowning all serves to make Styre a very credible menace in this very atmospheric story.

The GalSec colonists offer mixed performances, and the deception within their ranks is a bit too obvious by the time the supposed mystery in revealed, but full credit must be given to Kevin Lindsay who brings Styre to life immeasurably well with an unsettling malice and wickedness. He alone nearly makes up for some of the flawed special effects and the odd robotic design, but the hasty ending in which the Doctor claims that the Sontarans cannot proceed with their invasion plans without Styre’s report once Styre is defeated lacks any sort of punch. To think that the brutal Sontarans could not proceed with sheer force and numbers alone goes against much of Linx’s bombast in ‘The Time Warrior’ and diminishes the overall Sontaran threat quite significantly.

No two-part story could be expected to offer extremely heavy-hitting drama with lasting messages, but ‘The Sontaran Experiment’ certainly shows flashes of brilliance in its very condensed running time. It’s a mixed bag, but the Fourth Doctor and Styre both get plenty of time to shine in what ends up being a nonetheless enjoyable tale.