The Sontaran Experiment
The Sontaran Experiment was the third story in the twelfth season of Doctor Who. Shot entirely on location, it was the shortest story of the 1970s, with only two episodes. An outdoor shoot, all scenes were surprisingly recorded on videotape rather than film.
Script editor Robert Holmes was not a fan of six-part stories, believing that they were padded, so for season twelve, he decided to have one four-part story and one two-part story. With Christopher Langley’s “Space Station” already in the works, he looked to Bob Baker and Dave Martin to fill the gap. As an outline, Holmes asked them to set it on Earth and bring back the Sontarans. This would help them capitalize on the costly ship interior and Sontaran costume used in The Time Warrior.
Baker and Martin were commissioned to write the script on 23 May and asked to deliver episode one shortly after, on 5 June. Part two was in by 6 July and Holmes re-wrote it extensively, removing a sub-plot in which Vural was revealed to be a victim of mind-control. Despite Holmes’ earlier intentions, a new Sontaran costume was made for Kevin Lindsay. The previous one had exacerbated his heart condition, an illness that would kill him six months later.
The Doctor and his companions Sarah Jane Smith and Harry Sullivan trans-mat down from Space Station Nerva to a field on the now-healed Earth. The Doctor starts fixing the circle of trans-mat refractors with his sonic screwdriver while the others wander off to explore.
As they walk across the plain, Sarah hears a sound and sees movement on the top of a hill. Harry dismisses it. Two men in spacesuits, Erak and Zake, are observing the Doctor through the cross-hairs of their rifles. Erak leaves Zake to watch the Doctor while he reports the presence of the Doctor to another man in a spacesuit, Krans, who is tending a campfire. Meanwhile, Harry slips on the edge of a hole and tumbles into it. He is stuck, unable to climb out. Sarah observes that the edge of the hole had been covered deliberately. Harry has no choice but to stay put as Sarah goes to fetch the Doctor.
Zake’s observation of the Time Lord is interrupted by a strange floating robot that bears down on him. Zake flees, the robot pursuing him over the edge of a cliff. The Doctor finds Zake’s body when Erak and Krans arrive. Thinking the Doctor has killed Zake, they stun him with their rifles before he can explain. As they carry the unconscious Doctor away, they are watched by yet another spaceman, Roth.
Sarah gets back to the circle to finds the Doctor gone, his screwdriver abandoned. When Sarah returns to the hole, Harry is nowhere to be seen. Something had started throwing rocks down at Harry and in scrambling for cover, he found a way out of the hole, climbing through some rocks to the hills beyond. Sarah is about to climb down into the hole to look for Harry when Roth grabs her from behind, hiding her as the drone floats past. Once the danger is gone, Roth introduces himself to Sarah. It was he who covered the edge of the hole, trying to trap the drone. He tells Sarah that the robot serves an alien who lives among the rocks, an alien who has tortured him and killed two of his crew. Roth is obviously traumatized by his experiences. He vows he will not be captured again. When Sarah tells him about her friends, he informs her that the Doctor has been taken to the campsite.
At the campsite, Erak and Krans interrogate the Doctor, demanding to know what he has done to their crew mates. When the Doctor explains that he came down from Space Station Nerva, the spacemen (now joined by their leader, Vural) greet that news with great skepticism. Nerva, the lost colony of mankind, is a mere legend, like Atlantis. The spacemen are from one of the colonies, GalSec. The Doctor suddenly spots an odd looking button on Vural’s suit, identifying it as non-human technology. The button is actually a remote camera. Somewhere else, everything is being observed by something with a grey, heavy, four-fingered hand.
Roth brings Sarah near the campsite, but refuses to approach; he tells Sarah he saw Vural go to the rocks and the alien let Vural go. The GalSec men tell the Doctor that a GalSec freighter had gone missing. Detecting a distress signal from the supposedly uninhabited Earth, they came to investigate, but their ship was vaporized when they emerged, leaving nine of them stranded. The surviving crew began to vanish one by one. The Doctor offers to fix the trans-mat refractors and beam them all to Nerva, where they can contact another GalSec ship, but Vural says that they are not taking orders from the “Old People”. While the Nervans did nothing but sleep, the rest of mankind had spread across the galaxy and built an empire. At this point, Roth appears. While the three spacemen chase him, Sarah sneaks out from the rocks and frees the Doctor.
Roth loses the others and meets up with Sarah and the Doctor. Sarah tells the Doctor about the robot and the Doctor examines some residue on the ground, evidence of a terullian drive, except there is no terullian in this galaxy. The Doctor reasons that there must be some way out of the hole that Harry fell in, but as he climbs down, he too slips and falls to the bottom, losing consciousness. At that moment, the robot returns and snares Roth and Sarah with cables.
Harry has made it to the hills, where he spots a man-sized metal sphere among the rocks. As he watches, the robot arrives with Roth and Sarah in tow. The sphere’s door opens and to Sarah’s horror, out steps a Sontaran warrior.
When Sarah expresses her disbelief, the Sontaran tells her he is Field Major Styre of the Sontaran G3 Military Assessment Survey, identical to the other Sontaran clone she encountered, but not the same. Roth cries out that he will not be tortured again and makes a break for it, only for Styre to shoot him down. Roth had already been tested, so he was of no further use. Sarah, however, is far more interesting.
The three spacemen find the Doctor in the hole, but as they force him to climb out at gunpoint, the drone arrives and snares the trio. The Doctor goes back to the bottom of the hole. He finds the same exit that Harry used. Harry, in the meantime, finds another human chained to the side of the rocks, severely dehydrated.
Nearby, Styre has Sarah tied up to the rocks as well and has placed a device on her forehead. He seals her in with a force field. Styre goes to his transmitter station and reports to his Marshal. The Marshal is impatient for the intelligence report, but Styre tells him that some inconsistencies have arisen that he has to clear up before he submits it. Styre proceeds to subject Sarah to Experiment 7: resistance to fear. The device on her head begins to give Sarah hallucinations and she starts to panic. The Doctor, however, has reached her and uses the sonic screwdriver to breach the force field. When he rips off the device on her forehead, she gives a scream and falls unconscious. The Doctor, enraged, attacks Styre, but the Sontaran easily fends him off. Styre shoots him when he runs, the Doctor collapsing in a heap.
Harry finds Sarah unconscious and the Doctor’s apparently lifeless body. The chained-up spaceman has also died of thirst and Styre records the result of Experiment 5: human resistance to fluid deprivation. Harry prepares to attack Styre from behind, but is dragged back by the Doctor. Styre’s shot had hit a piece of scrap metal the Doctor had taken from Nerva, saving his life. The Doctor tells Harry to look after Sarah while he discovers Styre’s mission.
The robot brings the three remaining spacemen to Styre’s ship, where it turns out that Vural had tried to make a deal with Styre in exchange for his own life. However, Styre intends to experiment on Vural anyway, this time to determine the human rib cage’s resistance to pressure and muscular strength. He forces Erak and Krans to hold a gravity bar above Vural’s body, making it progressively heavier until it is all they can do to keep it from crushing Vural. Styre stops the experiment temporarily to go make another report and the Doctor eavesdrops on it.
The Doctor sneaks away again and meets Sarah and Harry. He tells them that Earth’s galaxy has somehow become strategically important in the Sontarans’ never-ending war against the Rutans. Styre’s experiments are to determine the physical limitations of humans, following which a Sontaran fleet will invade. The Doctor hatches a plan: he will distract Styre by challenging him to single combat. After a while, Styre will tire, and return to his ship to recharge his energy. While the Doctor fights Styre, Harry will go to Styre’s ship and remove a key component.
The Doctor confronts Styre, lying to him that his experiments are useless: the spacemen are the human’s “slave class”, the weakest of them all. The Doctor, on the other hand, is representative of the warrior class. Styre accepts the Doctor’s challenge. While the two fight, Sarah and Harry free the three spacemen, then Harry climbs towards Styre’s ship to carry out the Doctor’s instructions. Styre nearly gains the upper hand, but Vural attacks him, saving the Doctor at the cost of his life. Styre reaches his limits and heads back to his ship. As the time travelers back away from Styre’s ship, the Sontaran staggers out in pain, shriveling and deflating like a balloon before exploding.
The Doctor explains that the device Harry removed sabotaged the energizer, so the energy fed on Styre instead of the other way around. The Doctor makes his way to Styre’s transmitter. He tells the Marshal that not only has Styre’s intelligence mission failed, but that the invasion plans are in their hands. If the Sontaran fleet moves across the buffer zone, it will be destroyed. The Marshal swears revenge, and terminates the signal.
Erak and Krans thank the Doctor, but decide to wait on Earth for the Nervans rather than trans-mat up to the station. As they watch, Sarah, Harry and the Doctor vanish.