Inspirations - Earthshock

Take a look at Dalek stories over the years. Unless they were written by Terry Nation, there is a great deal of diversity in the types of plots employed. Even Nation managed to give us varied story types at the beginning - compare The Daleks with The Dalek Invasion of Earth and then with The Chase. It was only really when he got stuck on "small group of military types up against Daleks in a jungle planet setting" that the similarities started to become apparent. You'll be aware of the Terrance Dicks / Barry Letts story about commissioning Nation for Season 12. They read his latest set of scripts then invited him into the office for a chat. He was told that it was a perfectly good story, and it had been a perfectly good story when he had sold it to them the year before. And the year before that...
The trouble with Cyberman stories, is that they have been plagued with "sameness" for much longer. The Moonbase is pretty much a remake of The Tenth Planet, just set on the Moon instead of at the South Pole. There's a base, and the Cybermen want to invade it - and the base has something in it to which the Cybermen have an allergy. Later, we will get two stories in which the Cybermen want to capture a space station - The Wheel in Space and Revenge of the Cybermen. These space stations simply replace the Antarctic and Moon bases. Other allergies are introduced, and by 1975 they have a problem with radiation, gravitational forces, nail varnish remover, quick-setting plastic, electric shocks and gold. Only Tomb of the Cybermen (a Mummy / Egyptology pastiche) and The Invasion are different from the Cyber-norm - but even the latter sees them simply following the Daleks by having them invade London to march past a few tourist attractions.
The main reason the Cybermen never met the Third Doctor during the Pertwee era is because many of his stories revolved around invasions of Earth, and they had already done that in the Troughton era.
As Letts and Dicks planned Season 12, knowing that the series was going to move away from Earthbound stories, they decided to have a few old enemies lined up to help ease the transition to the new Doctor. Pertwee had been in the role for longer than either of his two predecessors (5 years to their 3 apiece) and was very popular with the viewing public, so it was felt that the relatively unknown Tom Baker would need all the help he could get. Time to bring the Cybermen back, as written by their co-creator Gerry Davis. The Revenge of the Cybermen turned out to be the weakest story of Season 12, mostly rewritten by a begrudging Robert Holmes, and the Cybermen slipped back into obscurity.

Jump ahead to the next Doctor transition period, and this time Peter Davison (at least already known) is having to take over from the most popular Doctor ever, who has been in the series for 7 years. A whole generation of children know only of Tom Baker as the Doctor. They could have gone with a Dalek story in Davison's first season to help launch him, but John Nathan-Turner and Eric Saward liked the Cybermen. They had access to all the Doctor Who stories in the BBC archives, and it is clear that Saward was taking notes.
Not only do we get references to previous Cyberman stories, we actually get clips from them as well. JNT was actively courting the ever growing organised fan base at this time, and was aware that the infrequent repeats of stories tended to be only of recently broadcast ones. What fans really wanted to see were archive stories from further back in the show's long history. He began by including some clips in Logopolis - of all the Fourth Doctor's companions, plus a selection of his enemies. This nostalgic clip-fest would continue in Seasons 19 (this story), 20 (the Brigadier's memories returning in Mawdryn Undead) and 21 (all the Doctors and their companions in Resurrection of the Daleks). Prior to Season 18 commencing, JNT had even managed to get a whole season of archive stories broadcast - The Five Faces of Doctor Who.
When the Cybermen recognise the Fifth Doctor, we get a short background piece about their encounters with him - leading to clips from The Tenth Planet, The Wheel in Space and Revenge of the Cybermen being shown on their scanner. The plot description which accompanies the Troughton story is actually that of Tomb of the Cybermen, but that story hadn't yet been rediscovered in Hong Kong and returned to the BBC vaults when this was made.
This scene may be the most blatant piece of Cyber-nostalgia, but Saward also works elements of previous Cyberman stories into his new story - most noticeably from Revenge. In that story, the Cybermen intended to blow up a planet which threatens them with explosives, making use of a human agent to help them. When the bomb ploy fails, they turn to Plan B and decide to crash a spacecraft into the planet instead. Earthshock also sees the Cybermen plan to destroy a planet which threatens them with a bomb, and resort to the same Plan B when the bomb is defused - only this time it's a space freighter which is to crash rather than a space station. Again they have a human agent helping them. Gold is once again a problem for the Cybermen. The Cybermen in The Tenth Planet had human hands - reminding us that they were once like us. The new design of Cyberman seen here has a transparent chin plate on its helmet, through which can be seen a humanoid jaw.
The Cyberman army is seen to be in suspended animation in silos on the freighter, and burst out of cylindrical tubes - just like the reactivated Cybermen emerging from their cocoons in The Invasion - another story in which they were abetted by a human agent.

Another inspiration for this story is Alien - the franchise-spawning 1979 movie from Ridley Scott. Saward was clearly aiming for a Ripley (Sigourney Weaver) vibe for Captain Briggs, commander of the space freighter. (I'm sure he wanted the ship to look like the Nostromo as well). What he got instead was the spectacularly miscast Beryl Reid. JNT saw his role as producer primarily as the money man, and the publicity man, leaving the actual stories to his script editors to sort out. One way of maintaining a high profile for the show in the newspapers was to cast well known actors and entertainers - whether they were right for a part or not. Reid was mainly known for comedic roles, but was perfectly capable of delivering a serious performance - just look at the BBC's adaptation of Tinker, Tailor, Soldier, Spy or The Killing of Sister George to see how good she could be. Briggs is supposed to be a tough, rough, hard-bitten, freighter captain - not your gran in space.
Watching Earthshock today, you might be mistaken for thinking that the sequel - Aliens - was also an inspiration, what with Lt Scott and his troopers crashing about - but that movie wasn't released until 1986.

When the TARDIS first arrives in the cave system, Nyssa spots a lot of dinosaur fossils. This will prove to be significant later on, as the Doctor gives a lecture on the theory of how the creatures came to become extinct. He is talking about the KT Event - the Cretaceous-Tertiary extinction which took place some 65 million years ago. Apart from some turtles and crocodiles, no large animals survived this event. A thin layer of sediment called the K-Pg boundary had been discovered in rock formations across the entire globe, and this layer contained the element Iridium. This is rare in the planet's crust, but is abundant in asteroids - so it was believed that the element must have been introduced from space. A vast crater was then discovered in the Bay of Mexico which appeared to have been the epicentre for the distribution of this layer, and it became accepted that a huge asteroid had struck the Earth - plunging it into a nuclear winter. Debris thrown up into the atmosphere would have reduced the sunlight, reducing temperatures, killing off plants and hence the animals which fed on them.
Other theories have emerged since, including the eruption of the volcanic Deccan Traps. This prolonged volcanic activity (it lasted some 800,00 years) would have resulted in the same nuclear winter conditions, but the extinction of species would have been more gradual. Another theory goes with multiple asteroid impacts - not just a single crashing space freighter. Others believe it was a combination of factors - asteroids and volcanoes, plus changes in sea level.

All this brings us to Adric. One of the functions of Earthshock which Saward had to include was the writing out of the series of Adric. JNT decided that he would have to die, rather than just leave to go home to Alzarius or be married off. It was clear that three companions were proving too many. Often one of them would have little to do - usually Nyssa, who gets stuck in the TARDIS building a robot-shaker machine in The Visitation, and is totally absent from Kinda while she has a bit of a lie down. Peter Davison actually fought for Nyssa to be retained on more than one occasion, as he felt she was the companion who worked best with his Doctor. The death of a companion was decided upon by JNT as he wanted the viewers to be reminded that the Doctor wasn't infallible, and that it could be dangerous to travel with him. The public had become complacent that the companions were just as invulnerable as the Doctor.
Adric wasn't the first companion to be killed off - that had been Katarina in The Daleks' Master Plan, in which companion of sorts Sara Kingdom also died. Katarina. however, had only appeared in 5 episodes, bridging two stories, and Sara had only featured in that one story, so Adric has the distinction of being the first long-running companion to be killed.

For the end credits to Part Four of Earthshock, JNT was inspired by an episode of Coronation Street. On 13th May 1964, the character of Martha Longhurst suffered a heart attack in the snug of the Rover's Return pub. The other characters who were with her in the bar didn't realise anything was amiss - thinking she had just fallen asleep. The end credits of the episode ran in silence. This had been only the second death of an established character in the programme. JNT remembered this episode and decided to do the same thing for Adric, as it was felt that the series' then current end titles music wasn't appropriate. The episode ends with a shot of Adric's broken gold-rimmed star badge against a black background, with the credits rolling in silence. Many have agreed that using the usual music would have been wrong, but just as many hate what we got. A more sombre arrangement of the theme would have been the sensible thing to have done.
(In the unlikely event that you have never seen this episode, firstly - sorry for spoiling it for you, and secondly - just turn off any music or TV you might have on in the background as you read this and stare at the above image for 45 seconds to recreate the experience).
Next time: Some idiot writes a Doctor Who story about a Concorde on prehistoric Earth, and another idiot actually commissions it. A well known villain makes a (non) surprise appearance, disguising himself for absolutely no reason whatsoever...