Conception of the Cybermen from the TV series Doctor Who

leading from

Doctor Who
and
Doctor Who And The Tenth Planet

a) Doctor Who loses the Daleks

In the mid 1960s Kit Pedler became the main scientific adviser for the television series Doctor Who.  He was a medical doctor, a pathologist and a scientist. With Gerry who became script editor in 1966 he set out to create a monster and hoped it would be a success. At the time the famous Daleks had been withdrawn from the television series because Terry Nation who invented them and had the copyright at the time hoped to make a series of films with the Dalek's because of their popularity. They made wonderful toys and everyone wanted to have a Dalek. There was no other monster that ranked with them in the series and so there was nothing the Doctor Who team could do about this other than come up with something new

b) Mysteries of a Tenth Planet 

In September 1965, The New Scientist magazine published an article briefly discussing the work currently being performed by G. Cheboterev of the Institute of Theoretical Astronomy at Leningrad

Gerry Davis the story editor and Kit had come to develop a rapport. Kit wanted to do his own Doctor Who script so they asked him to come up with some ideas and one was an idea rather like The Tenth Planet.  Through discussions with story advisers Davis had come up with an idea about an unknown planet that emerges to join the solar system and it comes into orbit along side the Earth and it begins to drain the Earth's energy supply. The astronomers notice that it is the reverse image of the Earth. The question was what happened next?

Another question to be addressed was who the main protagonists coming from this new planet would be. Kit's first ideas was a race of Star Monks, but something similar had been done in the program the previous year with a mischievous time travelling monk who tried to change history.  With this new planet draining the energy off another planet, Kit probably wanted to write about vampires but he was told in no uncertain terms not to go down that route.

c) Birth of the Cybermen

Gerry said to Kit "'Look, Kit, forget sci-fi, forget everything you've read. What do you feel about medicine?"

Kit's response was that he was afraid that medicine would become a matter of machines, and that you'd hook people up to computers which would be the doctor's and nurses.

Gerry would then respond 'Well, suppose people got totally cybernetic where they lose their souls? What would happen?'

Kits response seemingly merged with what Gerry would also claim he himself said in response to Kit, where ones words begun and the others left off will forever be lot.

Perhaps Gerry asked "'Well, suppose you had a race of beings who had started off with an artificial leg, and then another one, and then an arm, and this sort of thing, and finally there was perhaps a little core there, but the rest of them, the breathing and the brain functions and everything was cybernetic; what would they be like?"

And so perhaps Kit asked "You start with artificial arms and legs - very necessary and beneficial - but what if medical science eventually makes it possible to replace all of a human's organs - heart, lungs, stomach - with metal and plastic replacements! At what stage would the person stop feeling human emotions and become robotic? "

To which Gerry responded "That's it! Men with everything replaced by cybernetics, lacking the human feeling of love, pity, mercy, fear, compassion - and invulnerable to cold and heat. What terrible adversaries they would make! Cybernetic men. Cybermen!' '

Kit responded "They would be like computers  motivated by pure logic, If it was logical to kill you they would - if you got in their way."

What could motivate these loveless sexless beings. They decided on power, since history was fully of people who sacrificed love and family for the thrill of power.

Kit added "And survival. 'These men have sacrificed their arms, legs, their entire bodies in order to survive and become immortal. When a part wears out, they replace it. They could survive indefinitely. Perhaps we shall all go that way in the future"

Somewhere along the lines Kit also had the thought about a logical machine reasoning to itself and manipulating events outside it, but he couldn't envisage a machine producing a poem by Dylan Thomas.

Kit found himself sitting beside Una his wife in the garden of his home at 1998, Park Hill of Clapham, discussing space part surgery and conceiving the idea of someone with many mechanical replacements that he didn't know whether he was a human or a machine, as he further thought about these Cybermen, and he revealed how the idea of these creatures was the worst horror of what he was like, being , all intellect and no love.

By May 17th, a script was commissioned by the BBC, and Una coined the title of the story "The Tenth Planet"

Kit Pedler

d) Mythology continues to develop

At the idea continued to develop, Kit imagined that they were an ancient race on a dying planet who had made themselves immortal by gradually replacing their worn out organs and limbs with spare parts. Thy had become strong in the process and always behaved logically, but had lost their feelings and humanity as they became more and more machine driven, very much like the Treens and Mekon against whom Dan Dare and his associates in the Eagle comic stories waged their long battles. Kit cheerfully admitted to having read Eagle back in the 1960s.

art : Keith Watson
(source http://doctorwho.org.nz/ The Comic Connections)

 

 

 

e) Origins of the Wandering Planet

It seemed likely also that be borrowed the idea of a planet wandering into a solar system from the Dan Dare Stories -Red Moon Mystery, Rogue Planet and Wandering World  which featured planets that wandering into a solar system ( two of which attack the Earth), although the idea of wandering planets threatening Earth came in a 1933 Science Fiction novel When Worlds Collide by Philip Wylie and Edwin Balmer which was released as the film of the same name by George Pal which had the Earth colliding with a star instead while the humans plan to launch a colony on one of its orbiting planet. However all of these different sources were likely to be responsible in their different ways.

 

 

f) Furthering the thoughts about biomechanics

Later 1967, Kit further discussed the ideas, suggesting that if you're going to replace people with bits of nylon, plastic and stainless steel, you might as well go the whole hog and construct a completely survivable man. Humans are very weak with soft flesh and so on, and if you replaced them completely, then you produce something that is very strong physically, completely survivable and also totally undesirable

 

g) Traces of the Star Monks

In the end, what Kit and Gerry came up with would owe to the idea of monks and vampires but in a manner one might think. The idea of the Star Monks on a religious quest could still be found there for those who wanted to look for it. After all, the Cybermen came to Earth to save the human race converting us to their ways. Kit was beginning to see the world of medicine and science as something approaching religion , in that it generated a faith in those who used it, and saw its practitioner as above the rest of us.

Gerry Davis

h) Influence on others

Questions might be asked if HR Giger had at some point been inspired by the sight of the images of the Cybermen on television somewhere or in a magazine photo around leading up to the time be started on a robot suit for the movie Swiss Made 2069 and perhaps also when he came to paint Landscape XVI in 1972, and almost certainly they came to be the inspiration behind the Borg in Star Trek The Next Generation whose physical makeup and ambitions had remarkable similarities. Eventually Giger was asked to be involved in designing the Borg for Star Trek: First Contact but he decided to not be involved. Later noticeable elements of a Doctor Who story "Doctor Who and The Tomb of the Cybermen" would wind their way into the movie Prometheus.

Source Quotes

1. With time on the hands, Kit and Gerry started to discuss ideas. One of their starting points was a speculative science fiction theme based on the type of discussion Gerry had when he was sounding out people for the role of story adviser. " An unknown planet emerges to join the solar system and comes into orbit alongside the Earth. It starts to drain Earth's energy supply. Thus astronomers notice that it is the reverse image of the Earth - what happens next? 'I loved working with Kit because we both got excited about with with the images, ' he told Doctor Who Magaziine in 1987.' The image of that time was, of course, space flight, which was still comparatively new, so we suddenly thought it would be fun if we had this capsule going along and then finding its energy being drained by something.'(The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
2. The capsule would be monitored during its orbit around the Earth by an international tracking station set in the South Pole. Gerry Davis remembered how " we thought of a South Pole setting, because of the atmosphere it gave, with the tracking station and something - what?- affecting it. Alas, the South Pole is so inhospitable that nobody would expect anything to come out of those howling blizzards." Another inspiration for the polar setting was Kit's love for the 1951 classic science fiction film The Thing from Another World. Kit once told his daughter Carol that there was a sequence in that film that was one of the most frightening things he had ever seen. A group of scientists and military personnel arrive at a North Pole station to investigate what turns out to be a crashed spaceship, and there was something out there that was threatening them. "The brilliant thing for him was that you hadn't seen what the thing was, you just knew it was out there because the Geiger counters went completely bonkers  whenever it came close.' The conflict between the military and the scientists in that film might have informed Kit and Gerry in their thinking too. Wearing his script editor's hat, Gerry found the Tracking Station would serve as one big expensive set, with smaller, less expensive ones surrounding it (cabins, store rooms etc.) This was how a script editor would have to think with so little money available for the design work. (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
3. The next question to be addressed was who the main protagonists coming from the new planet would be? With the future of the Daleks uncertain the production team wanted a new regular monster that would be as popular. Kit's first thought was a race of Star Monks, but something similar had already been done in the program the previous years with a mischievous time travelling monk who tried to change history. With this new planet draining another's energy, this may have been the story in which Kit wanted to write about vampires, but he was told in no uncertain terms not to go down that route. What Kit and Gerry came up with would owe to monks and vampires, but not in the manner you might expect (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
4. 'By that time" says Gerry, " we had a real rapport and we could strike sparks off each other and I said, "Look Kit, forget sci-fi, forget everything you've read. What do you feel about medicine?" and I soon found that he was afraid that medicine would become a matter of machines; that you'd hook people up to computers and they would be the doctors and nurses.' This wasn't too far fetched a fear. There were some clinics in America planning to do just this. Kit thought of a computer controlling a hospital ward, and  the power of life and death it could yield, and decided to act upon it. The idea was not pursued further - at least not for Doctor Who, but the idea of victims  of dehumanised medicine was kept in mind since there was something in the air of the mid-1960s that touched upon it. (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler) 
5. Gerry Davis. Meanwhile, we needed a new monster. I asked Kit what his greatest phobia was as a doctor. "Dehumanising medicine" he answered" You start with artificial arms and legs - very necessary and beneficial - but what if medical science eventually makes it possible to replace all of a human's organs - heart, lungs, stomach - with metal and plastic replacements! At what stage would the person stop feeling human emotions and become robotic? "
   "That's it! " I said. "Men with everything replaced by cybernetics, lacking the human feeling of love, pity, mercy, fear, compassion - and invulnerable to cold and heat. What terrible adversaries they would make! Cybernetic men. Cybermen!' '
   "They would be like computers, motivated by pure logic." said Kit. "If it was logical to kill you they would - if you got in their way." 
   What would motivate these lovesless, sexless beings? We decided on power. History after all, was full of human monsters who sacrificed love and family for the thrill of power.
   'And survival." added Kit. "These men have sacrificed their arms, legs, their entire bodies in order to survive and become immortal. When a part wears out, they replace it. They could survive indefinitely. Perhaps we shall all go that way in the future" (DoctorWho -Cybermen, by David Banks, Forward by Gerry Davis, 1986 p9-10)
6. Kit Pedler supplied the introduction to a Dan Dare reprint volume in 1979 (TheMan From Nowhere) admitting that the Cybermen were 'very like the Treens s'. Likewise,three Dare stories –Red Moon Mystery, Rogue Planet and Wandering World featured planets that wandered into a solar system (two of these attack Earth). Pedler cheerfully admitted to reading the Eagle in the 1960s. (Time Unincorporated 1: The Doctor Who Fanzine Archives (Volume 1: Lance Parkin))
7. Gerry Davis : Kit Pedler wanted to do his own (Doctor Who) script so we asked him to come up with some ideas and one was something rather like The Tenth Planet but the characters he used were sort of star monks... By the time we had a real rapport and we could strike sparks of each other and I said, 'Look, Kit, forget sci-fi, forget everything you've read. What do you feel about medicine?' and I soon found that he was afraid that medicine would become a matter of machines; that you'd hook people up to computers and they would be the Doctors and nurses. We wrote a Doomwatch later about cybernetics called The Iron Doctor about a computer which actually makes a decision to terminate certain people after summing up their cases and deciding there was no sense in wasting the time and money. It was like an electronic Margaret Thatcher! Kit originally came up with that idea for Doctor Who, then I said, 'Well, suppose people got totally cybernetic where they lose their souls? What would happen?' And that's how the Cybermen were born between the two of us.' (Gerry Davis interview Doctor Who Bulletin issue 59, 1988.  from http://doomwatchblogger.blogspot.co.uk)
8. Gerry Davis: I asked Kit what frightened him and to my surprise he started talking about advances in medical techniques. He was worried about where the late remedial procedures would take us. (The Essential Doctor Who: The Cybermen, p14)
9. Gerry Davis: Kit wondered how far down the road of replacement surgery a person would have to go before they started to lose their humanity. And what would happen if it became possible to not only repair the human body but to also enhance it. (The Essential Doctor Who: The Cybermen, p14)
10. Revolutionary breakthroughs in biology were being promised before the decade was out. It would be possibly to transplant organs from one body to another, fertilise eggs outside of the mother's womb, but there were those who though we could replace a defective biological organ with something inorganic. This issue would culminated in a fascinating book in 1968 by former BBC Horizon editor Gordon Rattray-Taylor called The Biological Time Bomb which would ask this very questions, where were the biological sciences going to take mankind? (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
11. The term Cyborg - or cybernetic organism - was coined in 1960 by Manfred Clynes and Nathan S. Kline, who fantasised about self regulating human machine systems designed to survive the hazards of space travel. Clynes argued in his introduction to the 1965 book Cyborg: Evolution of the Superman that a cyborg would be more flexible that a human being because 'it was not bound to a lifetime of hereditary.' Quite the reverse, it could pick and choose its own augmentations. The Guardian's Anthony Tucker, also writing in 1965 was at pains to explain to his readers that since the science of cybernates was 'comparatively new... it possess a lunatic fringe and a cloud of popular misconceptions. Its purpose is not to create mechanical or electronic devices with imitate human behaviours... its purpose is to develop very precise theories of feed-back control which have practical application and which, by analogy, may lead to an understanding of the extremely complex ways in which human beings work.' Kit was applying cybernetics to his study of the retina. he wanted to build an electronic eye to enable the blind to see, but supposing the organ to be replaced is not defective in the first place. (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
12. Dr. Alex Comfort, one of the men Gerry David had seen before he met Kit Pedlar, had been writing about spare part surgery since the early 1960s. He did it again in an August edition of New Scientist, in an article titled Modified Men.  (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
13.  'Some of it may be used to enhance the performance of the whole rather than supply the deficiencies of the sick,' Comfort mused, before asking a fundamental questions. What it would mean for the person receiving such a replacement? 'Who am I? Am I a true human being?' If you have an artificial organ, you may feel perfectly normal, but how would others regard you? One is regarded as being less human for having a wooden leg or for being blind; such handicaps are "judgements" and so on." A disability can be regarded by 'normal people' as horrific or abnormal, even just a small disfigurement on the face.  (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
14. Kit told World Medicine in 1967, "If you're going to replace people with bits of nylon, plastic and stainless steel, you might as well got the whole hog and construct a completely survivable man. Humans are very weak with soft flesh and so on. If you replace them completely you produce something that is very strong physically, completely survivable, and also totally undesirable.' Scientists in America were certainly looking at ways of making humans much stronger than they currently were. In October 1965, Niel J Mizen wrote and article for New Scientists titled Amplifying Man where he discusses this work being carried out by engineers  of the US Air Force at Cornell Aeronautical Laboratories in Buffalo, New York. They were studying the feasibility of a powered 'exoskeleton' with hydraulic joints matching those of a man 'that provide the necessary torque and power under the control of a servo mechanisms. The server responded to movements of the wearer and cause the powered structure to follow his natural movement." The project was called Man Amplifier. The photos illustrating the article shown man in a flimsy jump suit with bands across the joints of his arms and joints with tubes running along the length of his body. It looked suspiciously similar to what would be seen on screen in Doctor Who in October, where the exoskeleton was a replacement for muscles, and not simply an enhancement. (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
    
15. Supposing the space travellers from this new planet, threatening the Earth, were once human beings, but were not cybernetic humans? But with out space travellers from the new planet, it has gone too far, and they were completely dehumanised. What if they had extended the 'plumbing" surgery, as Kit described spare part surgery to the Sheffield Morning Telegraph, also in 1967, to the human brain. Something similar had been happening abroad, he said. "If people are going to start seductively altering brains in the interests of curing mental disease, we have to be very careful what this alterations is going to do. I have no evidence whatever that these human experiments were harmful; and this has nothing to do with ordinary treatment of patients by doctors. But where do you draw the line? What worries me is that the jump has been made from animal  to human experiments without, I think, any serious examination of consequences." Experiments had been performed, he claimed, in planting electrodes permanently into certain areas of an animal's brain and to transform the subjects, by remote control , into a state of rage or ecquiescence. Imagine if they could just switch off their emotions. (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
    
16. Kit was thinking of these ideas when he was at home in the garden of 119 Parkhill in Clapham with Una. "we were discussing spare part surgery and conceived the idea of someone with some many mechanical replacements that he didn't know whether he was a human or a machine, " he told Radio Times in 1968. Una remembers the discussion, and the consequences of becoming a man machine: "He was sitting beside me in the garden and he thought about it,  and he said it was his worst horror of what he was like, that is, all intellect and no love. " Una also coined the title of the story Kit was thinking about: The Tenth Planet. It would be Earth's long lost twin planet, which looked like Earth, and had evolved its own human race. Just to complete the picture, the New Scientist asked Is There a Tenth Planet!" in September 1965, briefly discussing the work currently being performed by G. Cheboterev of the Institute of Theoretical Astronomy at Leningrad . (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
    
17. Gerry Davis: We did set out to create a monster, and we hoped it would be a success. The Daleks had been withdrawn because Terry Nation at this time had hoped to make a series of films with the Daleks because they were so enormously popular. They made wonderful toys. Everybody wanted to have a Dalek. So it was a real blow to the programme when Nation decided that he'd take the Daleks out, and as he owned the copyright, there was nothing we could do about it. There was no other monster that had come up prior to that, that ranked with the Daleks, so the time had come to create another one, so Kit Pedler and I got together. Kit Pedler was a medical Doctor, a pathologist, a scientist, and he had a feeling about medicine that if you started replacing too much of the human body, where do you stop? When does the result turn into a robot? He felt that you'd lose humanity if you kept replacing arms and legs. So I played on that. I said, 'Well, suppose you had a race of beings who had started off with an artificial leg, and then another one, and then an arm, and this sort of thing, and finally there was perhaps a little core there, but the rest of them, the breathing and the brain functions and everything was cybernetic; what would they be like? So we speculated and we decided they'd be very frightening people to run into on a dark night!
    "We spent a lot of time trying to devise a body where the limbs didn't come from the place where you'd expect them to come, or some other sort of peculiarity that made them seem other than human. But of course it went to the costume designers, and they did a good job. For that first manifestation the best thing they could think of was to put this rubberised stuff - I think part of it was a wetsuit - and golf balls and bits of tubing on - it was quite a hotchpotch, those first Cybermen.
    "What Kit Pedler and myself did for the very first appearance of the Cybermen was to take one out into a crowded South London street market. I wanted to see what the reaction was, so we got an actor, a tall fellow, and dressed him up - I nearly volunteered but it was very hot inside. I was briefly an actor for a while, and I played the Frankenstein character. When I was doing this, I sat through a Frankenstein film, and I watched the walk, and the walk of Frankenstein is very menacing, and it worked. So when we came to the Cybermen, I thought, well, we don't want them loping along because there's no menace in that, so I got the actors, and tried to show them how I'd done this thing, and it was very good because the Cybermen always walked in this way. I coached them a bit, and showed them how to do this walk. So this Cyberman walked through this market, and it was very funny - this weird-looking monster was walking among them and they were edging away. I have photographs of it, which are going to appear in a book about the Cybermen by Andrew Skilleter. I discovered them tucked away in a file, taken of this very occurrence.
    "The Tenth Planet was the first one that Kit Pedler and myself wrote, and it starts off with them landing at the South Pole. There was a big snowstorm and out of the snowstorm came these figures and they didn't look as menacing, I think. For me, the Cybermen really took off when they got that molded helmet - before that, you saw it as a man. They arrived out of the snow and they were impervious to cold when everybody else is freezing their guts off these would walk in!
    "After about three years, Billy Hartnell wasn't a well man, and he wanted out, and that was a bit of a disaster to a programme that was called Doctor Who. Everyone identified with him as Doctor Who, and it's very hard for people to accept a different Doctor. The answer was to rejuvenate him. Then we looked for an actor and finally we found Patrick Troughton. He looked like a hungry gypsy He was very fey - you couldn't tie him down to anything; he'd never make a statement." (Time SpaceVisualiser #2, September 1987, http://doctorwho.org.nz/archive/tsv2/gerrydavis.html )
18. Kit took these thoughts to Gerry David, who liked the thinking and imagined how their conversation would have gone in his foreword for Cybermen some twenty two years later:
    "You start with artificial arms and legs - very necessary and beneficial - but what if medical science eventually makes it possible to replace all of a human's organs - heart, lungs, stomach - with metal and plastic replacements! At what stage would the person stop feeling human emotions and become robotic? " 'That's it!" I said, "Men with everything replaced by cybernetics, lacking the human feeling of love, pity, mercy, fear, compassion - and invulnerable to cold and heat. What terrible adversaries they would make! Cybernetic men. Cybermen!' They would be like computers  motivated by pure logic, ' said Kit, 'If it was logical to kill you they would - if you got in their way." What could motivate those loveless, sexless beings? We decided on power. History, after all was full of human monsters who sacrificed love and family for the thrill of power. ' And survived,' added Kit. 'These men have sacrificed their arms, legs, their entire bodies in order to survive and become immortal. When a part wears out, they replace it. They could survive indefinitely. Perhaps we shall all go that way in the future." (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
19. Gerry Davis was an experienced television writer when he came to Doctor Who as Script Editor in 1966. Wanting to explore stories rooted more closely in real science, Davis contacted Dr Kit Pedler. The resulting collaboration resulted in several notable Doctor Who scripts, and in particular the creation of the Cybermen. Gerry Davis returned to Doctor Who in 1975 and novelised several of his and Pedler's Doctor Who stories for Target books. Gerry Davis died in 1991.(http://www.randomhouse.co.uk/authors/gerry-davis)
20. Kit Pedler created a little back story for these creatures, thinking back to Dan Dare. "They were an ancient race on a dying planet, who had made themselves immortal by gradually replacing their worn out organs and limbs with cybernetic spare parts. They had become strong in the process and always behaved logically, but had lost their feelings and humanity as they became more and more machine driven - very much like the Treens and Mekons against whom Dan and Co. waged their long battles."(The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
21. They became very excited by the idea of the Cybermen. They had the potential for appearing in more than one story. On a blackboard in Gerry's office, they sketched out initial designs of how a Cyberman would look. Kit was keen to break up the human form, to make these creatures as inhuman as possible. They wanted the heads and arms to appear lower down the body, for example, but realised that it would be difficult to actually realise for the designers. There was no doubt that silver was to be their colour. They became excited over the image of indistinct silver shapes marching through a polar blizzard... Kit knew about marching from his National Service days, and was struck by how robotic a parade had seemed. They were still to have attractive human faces, but with a metal skull cap suggesting computerised brains.
    (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
22. The idea of the Star Monks on a religious quest can still be found if you want to look for it. After all, the Cybermen come to Earth to save us from a dying world and convert us to their ways. Kit was beginning to see the world of medicine and science as something approaching a religion, in that it generated a faith in those who used it, and saw its practitioners as above the rest of us. (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
23. It has been speculated that the Cybermen might be representations of the communists, the West's current adversary, but it is clear that what they represent, Kit's ultimate visions of himself and his ilk; cold logical scientists - technocrats who had surrendered their humanity to machines in order to survive, and had become monsters. The Cybermen were not a warning to the television viewers of 1966, just an expression of a nightmare.. (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
24. The Cybermen would claim to be invulnerable to the elements and from bullets, but radiation was to be their weakness. Alan Barnes argued in Doctor Who Magazine in 2005 that this could not have been the case since irradiating transplant patients with radiation weakens the body's defences and helps prevent organ rejection. Unfortunately, the end results was that the patient was so weak that they died anyway from ordinary infections. Cybermen had transplants, may have been irradiated and could not tolerate any more. Their greatest vulnerability turned out to be their dependence upon power from their own planet, Mondas. The Cybermen had returned to their twin planet in their original solar system and tried to take away our energy. Precisely how this worked is never explained or rationalised in the finished story, and since these Mondasian Cybermen could not control the process, it sounds as if it was some kind of natural process. This resulted in the destruction of their own world, Mondas, as it absorbs too much energy. The Cybermen seemed to be powered by Mondas, or at least from some generator on it, and once that was destroyed they stopped working.. (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
    
25. Having worked out the Cybermen would be defeated in the long run, and knowing that they would be aware of this probability, Kit and Gerry came up with the Z Bomb, the ultimate doomsday weapon, one of which was kept inside the Tracking Station. Part of the story would feature the humans arguing over whether to use this against this new planet, until the Cybermen plan to use it against the Earth itself. The humans have to prevent this from happening and wait for whatever bizarre natural process destroys Mondas (The Quest for Pedler: The Life & Ideas of Dr Kit Pedler)
26. Kit Pedler: I was thinking, that although I could imagine a logical machine reasoning to itself and manipulating events outside it, by no stretch of the imagination could I envisage a machine producing a poem by Dylan Thomas. (Doctor Who: A Book of Monsters)
27. Kit Pedler: We conceived the idea of someone with so many mechanical replacements that he didn't know whether he was a human or a machine. (Doctor Who: A Book of Monsters)