Whilst Barbara remains on the spaceship, the Doctor, Ian and Susan travel down with with John and Carol to the Sense-Sphere. John receives treatment from the Sensorites (helping to undo the damage they’ve created) whilst the Doctor agrees to investigate a mysterious plague which is killing an increasing number of Sensorites.
One of the main problems with The Sensorites is how simplistic some of the plotting is. We’re asked to accept that the Sensorites are a technically advanced race, but they’ve spent the last ten years dying from a mysterious disease for which they’ve been unable to either identify or find a cure for. The First Elder (Eric Francis) mentions that the Elders enjoy special spring water, but Ian, who’s very thirsty, doesn’t want to wait for it to arrive and drinks some of the normal water. He then keels over, which leads the Doctor to deduce that the water supply is poisoned.
If one wanted to be generous then we could assume that, due to the Sensorites different physiognomy, the symptoms of the poisoned water don’t manifest themselves so quickly. Otherwise, if a Sensorite toppled over immediately after drinking the water you’d have thought they would have twigged by now! Even so, testing the air, water, food, etc should have been amongst the first things to have been checked.
Again, if you wish to take a more sympathetic reading of the text, it could be that Newman was attempting to show how an isolationist nation like the Sensorites had partly brought this problem on themselves. Although they are technologically advanced, it’s only the input of an outsider which provides them with a solution – therefore their fear of aliens had prolonged their suffering.
But if this section of the story doesn’t quite convince, we also have some interesting exchanges between the Sensorites themselves. Although rudimentary, this dialogue serves to remind us that whilst they are nominally the “monster” of the story, in their own eyes they regard themselves as the heroes and it’s the humans who are the potentially threatening force.
2ND ELDER: In one degree I confess I am anxious. These creatures, these Earth people, are loud and ugly things. Why could we not have met them in the desert or in the mountains?
1ST ELDER: It is a failure of all beings that they judge through their own eyes. To them, we may appear to be ugly. What we must create between us is trust. That is why I have invited them to my palace.
2ND ELDER: But are we sure these Earth creatures are beings as you say? There are animals in the deserts and mountains, but we do not invite them in to our palaces. Perhaps these Earth creatures are animals too?
There’s also a brief insight into how their nation is ordered. “The Elders think and rule, the Warriors fight, the Sensorites work and play.” The Sensorite goes on to tell the Doctor, Ian and Susan that all are happy, but Ian’s ironic misquoting of Orwell (“some are happier than others, eh?”) helps to suggest that there may be chinks in their well-ordered society.
And although the Sensorites may look alike, they don’t possess a hive mind. This is made clear by the bitter words of the City Administrator (Peter Glaze) who regards the outsiders with resentment and fear. And it’s his low-level villainy that will provide the jeopardy over the final three episodes.