Susan announces that if she does not accompany the Sensorites to their planet, everyone will be killed...
She exits the bridge and the door closes behind her, but Ian opens it and halts them. The Doctor orders his grand-daughter back onto the bridge then confronts the Sensorites. When they threaten him, he tells them that he knows their weaknesses. To prove this he has Ian turn the lights off, and the aliens panic in the darkness. He switches the lights back on again, and advises that they seek new orders.
Their leader - the First Elder - instructs that Maitland and Barbara should remain on the spaceship whilst everyone else comes to the Sense-Sphere for talks. They will try to cure John.
On the planet they learn that the Sensorites are antagonistic towards the spaceship crew because of an incident 10 years previously. Another ship had arrived from Earth and its crew had discovered the molybdenum deposits. They had fallen out with each other over what to do with this discovery, and the ship had exploded when it attempted to take off. The Sensorites assumed that all the astronauts had been killed after arguing with each other.
Since that time a strange plague has been killing many of their people.
The Second Elder is initially suspicious of the newcomers, whilst the City Administrator is vehemently opposed to them. He has the city's defence weapon home in on them - a hidden disintegrator device which can kill remotely when programmed to strike a particular location. It is controlled by one of his allies from a small chamber beneath the Elders' palace courtyard.
The Second Elder realises the visitors are friendly and so goes to the disintegrator room and notifies the Administrator to stand down, confiscating the vital firing pin. He lets it be known that he is concerned about the Administrator's failure to obey his superiors. The Administrator determines to destroy the visitors some other way...
Refreshments are given to the Doctor, Ian and Susan, whilst Carol accompanies John to the laboratory where scientists will help him.
The First Elder notices that his guests have been given inferior water, and orders replacement from his personal crystal spring. Thirsty, Ian cannot wait and takes a drink.
He is suddenly taken violently ill and collapses onto the floor.
The Doctor asks if Ian's symptoms match those of the plague, and the First Elder confirms that they are. He is dying, and nothing can save him...
Next episode: A Race Against Death
Data:
Written by: Peter R Newman
Recorded: Friday 12th June 1964 - Lime Grove Studio D
First broadcast: 5:15pm, Saturday 11th July 1964
Ratings: 7.4 million / AI 56
Designer: Raymond P Cusick
Director: Mervyn Pinfield
Additional cast: Eric Francis (First Elder), Bartlett Mullins (Second Elder), Peter Glaze (City Administrator), Arthur Newall (Fourth Sensorite), Gerry Martin & Anthony Rogers (Sensorites).
This episode saw the series move back to Lime Grove Studio D. A limited part of the spaceship set (part of the bridge and a corridor) was transferred there, but only appeared in the first half of the episode. The main new sets were the Elders' reception hall, plus the small disintegrator room and a section of courtyard.
The latter featured a working fountain, and had a backdrop of the wider city. The inclusion of the fountain was because it was supposed to form part of the poisoned water plot, but this was dropped. Ray Cusick opted to make the Sense-Sphere a place of arches and domes, with as few straight lines and box shapes as possible. He stated in interviews that he had been inspired by the Catalan architect Antoni Gaudi, whose most famous work was for the Basilica i Temple Expiatori de la Sagrada Familia in Barcelona - a building which is still incomplete.
The heat in the Lime Grove studios was great at the best of times, but recording was now taking place in the summer months. All of the Sensorite performers rehearsed without their masks - donning them only for recording.
We learn something of the Sensorite culture. The First Elder wears a pair of black sashes crisscrossing his chest, whilst his deputy - the Second Elder - wears a single sash. It appears to be a Geniocracy - rule by the intelligent - as the First Elder is said to have been made leader due to his "great brain".
The City Administrator has a black band around his collar. Scientists wear a symbol on their chest which looks like a cross between an alembic (chemical container) and a caduceus (the serpent symbol associated with medicine).
The First Elder explains that the majority of his people have no specific caste like Warrior or Scientist but all are equal. It is quite clear from the casting that Sensorites are not physically identical.
The First Elder will maintain that he trusts his people implicitly, and they are all happy with their lot, so it seems odd that their city - including his own palace - is covered by a death ray weapon.
The City Administrator emerges as a new threat for the TARDIS and the spaceship crews. He is fiercely loyal to his people, though not necessarily to their leadership, as he deliberately ignores their instructions. He is quite prepared to kill the visitors in front of his ruler, simply because he does not trust them. The Sensorites have been suffering ever since humans visited them 10 years ago, and so he is implacably opposed to their kind. His hatred goes so far that he has no thought of the consequences to himself were he to have used the disintegrator on the Doctor and friends - killing them as they chatted to the First Elder.
Though he would argue there were very definite concrete reasons for distrusting people from Earth, his real motive is that he is suffering from xenophobia - a fear of the unknown often characterised by hatred towards foreigners / strangers. In this he's not the first person to exhibit such paranoia in the series. Ian believed it was at the root of the Daleks' murderous hatred of the Thals - a "dislike for the unlike".
As well as a villainous character being introduced we also have a new threat against the travellers, in the form of a deadly disease. The Sensorites being potentially belligerent aliens formed the threat for the first two episodes, but now that we know that they are - for the most part - friendly, then new dangers have to be introduced to maintain interest.
The series will find many interesting ways of sustaining the adventure over lengthy running times. So far we have had the false ending in the first two stories - the TARDIS crew thinking they have reached the safety of the ship, only to discover that it is not to be (because there are armed cavemen in the way, or because a vital component has been left behind). The Daleks also featured a brief quest set-up halfway through the latter part of the story to spice things up a bit. The quest scenario also benefitted both Marco Polo and The Keys of Marinus, as the action could move from place to place each week, throwing up new dangers at each stop. The Aztecs, on the other hand, kept the same threat throughout - the machinations of Tlotoxl and Ixta - but simply escalated it to maintain interest.
- It had been suspected that this episode might be delayed due to the summer programme of sport, although the week before broadcast it had still been hoped that it would go out at 7:10pm after another extended edition of Grandstand. As it was, that slot was given to Juke Box Jury and Hidden Danger was deferred for one week.
- One benefit of this was that the series regained the four week gap between production and broadcast which had been reduced to three weeks when The Dead Planet had to be remounted.
- The episode sees an increase of half a million on the previous one, but it also has the lowest audience appreciation figure of the entire story.
- After recording this episode it was Jacqueline Hill's turn to get a two week holiday. Barbara is to remain aboard the spaceship with Captain Maitland whilst the others are transported down to the Sense-Sphere. As with Hartnell during the making of The Keys of Marinus, she will simply be written out of the action for two episodes.
- Peter Glaze was best known for comic roles. He was one of the stars of Crackerjack, the BBC children's variety show which had been running since September 1955. Not long before appearing in the series, Glaze had performed a Doctor Who joke on the series: "Who's in the cupboard?". "Well, it's not Doctor Who, is it?". When it comes to comedy, the past is indeed another country.
- Arthur Newall's "Fourth Sensorite" was the City Administrator's villainous accomplice, sometimes referred to as the Engineer.
- Gerry Martin was a non-speaking Scientist. Joe Greig and Ken Tyllsen continued to play speaking Sensorites such as the Chief Scientist.
- It was during rehearsals for this episode that actor Brian Proudfoot was brought in to observe William Hartnell's physical mannerisms as the Doctor. He would be playing him in some brief location shots for the next story in production. Hartnell initially found this process extremely irritating, but then became more helpful as he wanted Proudfoot to get it right.
