So… who needs a hug? It’s the end of term and, for all the excitement over Christmas, it’s clear we’re going to need an extra box of tissues… But that’s still months away. Right now it’s time for the final instalment in this series of viewing notes explaining away some of those back references and things that seemed a bit familiar from this week’s episode. And then there’s the commenters. Much as it can be painful to wake up on a Sunday morning and realise that I missed a reference to The Horns Of Nimon, you guys keep me on my toes and provide more than a few chuckles along the way, so thank you. All of which waffling brings me back to this week’s references – they were coming thick and fast, so if I’ve missed any, you know how to let me (and the rest of the world) know… The tenth Doctor (in the guise of human teacher John Smith) faced killer scarecrows in 2007’s Human Nature, where they were henchmen of the villainous Family of Blood – one of whom was left permanently trapped as a scarecrow by the vengeful Doctor at the end of the tale. The Master himself also once dressed up as a scarecrow, in 1985’s The Mark Of The Rani. The Doctor may not have burned, but the Master certainly has – by the time the fourth Doctor encountered him in The Deadly Assassin the Master was badly burnt and decaying. And in 1984’s Planet Of Fire the fifth Doctor watched on as the Master appeared to burn to death in a numismaton gas vent. It’s little wonder he doesn’t feel much like standing with him, really… The Master once again has his laser screwdriver, introduced in The Sound Of Drums (with the Master explaining ‘Laser screwdriver. Who’d have sonic?’). As well as being a ruthlessly efficient killing weapon, the screwdriver was used to artificially age the tenth Doctor into a wizened, Dobby-esque figure (That’s Dobby from Harry Potter, not Dobby from Peep Show). Missy, meanwhile, appears to have a sonic umbrella – she’s been carrying the umbrella since her first appearance in 2014’s Deep Breath, but this is the first time it’s been shown to have sonic capabilities, though it did allow her to float from the sky in that year’s Death In Heaven. The twelfth Doctor isn’t the first incarnation to earn the nickname ‘Grandad’ – the eleventh Doctor refers to the War Doctor as such in 2013’s The Day Of The Doctor. There’s a visual reference to that story in the scene where the two Masters (and the Doctor) point their devices at the Cyberman; when the tenth and eleventh Doctors aim their sonics at the War Doctor, he asks them “Why are you pointing your screwdrivers like that? They’re scientific instruments, not water pistols!” Of course, the twelfth Doctor was also referred to by Bill as her grandad in Knock Knock earlier this series, and the first Doctor (Who we’ll get onto in a bit) was an actual grandfather. The Masters wonder how many regenerations the Doctor has left, but the truth is nobody knows anymore. The Doctor reached the end of his regeneration cycle in 2013’s The Time Of The Doctor, but Clara pleaded with the Time Lords and they granted him a new one – as they had the Master in 1983’s The Five Doctors. But it’s unknown how many lives are in this cycle – in 2015’s Hell Bent Rassilon asks the Doctor “How many regenerations did we grant you?”, so it’s possible not even the Time Lords know. As mentioned last week, the Simm Master was last seen being blasted back into the Time War with Gallifrey in The End Of Time. At that point he was suffering from physical instabilities – the ‘little condition’ the Doctor refers to here – as a result of his ex-wife sabotaging his resurrection ceremony. Spare Parts is still canon! Next on the list is Telos, the setting for 1967’s Tomb Of The Cybermen, in which Professor Parry explained to the Doctor’s companion Jamie that Telos was the home planet of the Cybermen – a detail that was carried through to several official written works (including ones by Cybermen co-creator Gerry Davis) during the 1970s. 1985’s Attack Of The Cybermen returned to Telos, and explained that the Cybermen had invaded the planet. As mentioned later in this story, the Doctor sealed these ‘Telosian’ Cybermen away in their ice tombs, where they had been put into hibernation. A more mysterious entry on the list is the enigmatic ‘Planet 14’. When the Cybermen turned up in 1968’s The Invasion, they looked significantly different to the models that had appeared in The Wheel In Space earlier that year. In The Invasion, the ‘Cyber-Planner’ tells their human ally Tobias Vaughn that the Doctor and Jamie had been recognised from Planet 14 (Where, we learn in this episode, the Doctor defeated the Cybermen). If the P14 Cybermen were a different evolution to the Mondasian (or Telosian) Cybermen, this would explain their new designs. Jamie sacrifices his life to destroy the device, and this is where things get difficult – because not only is Marinus apparently the real name of Planet 14, but the world-shaping device transforms it into the planet known as… Mondas. In suggesting that these are all separate planets, Moffat has truly given with one hand and taken away with the other… Other Cyber-skirmishes the Doctor refers to while blowing up Cybermen are the Vogan incident from 1975’s Revenge Of The Cybermen, the Battle of Canary Wharf from 2006’s Army Of Ghosts/Doomsday, and a skirmish on the moon as depicted in 1967’s The Moonbase. There are three models of Cybermen used in this story – the Mondasian Cybermen, the logo-less Lumic-style Cybermen introduced in 2011’s A Good Man Goes To War, and the most modern versions, which were brought in for 2013’s Nightmare In Silver. I will always remember… As discussed last week, Bill isn’t the first person to rebel against Cyber-programming – Danny Pink, Yvonne Hartman and the Brigadier before her all managed to break free (and the first two cried, disproving the Doctor’s claim that it’s impossible for Cybermen to cry in this episode) – but perhaps the most notorious case of this is Kroton, the ‘Cyberman with a soul’ in the Doctor Who Magazine comic strips, who first appeared in 1979 before returning twenty years later to team up with the eighth Doctor, where he eventually took on the Master before receiving omniscience and becoming akin to a god. The Doctor mentions that Bill has effectively created her own perception filter – these were first introduced into Doctor Who (having previously been mentioned in Torchwood as an occurrence which hides the lift down into Torchwood Three from public view) in Human Nature, in which a perception filter caused John Smith to ignore the fob watch which, if opened, would change him back into the Doctor. Later that year, the Doctor, Jack and Martha used them in order to get close to John Simm’s Master. Jelly babies first appeared in Doctor Who in 1968’s The Dominators being munched on by the second Doctor. They remained something he liked when he returned in 1972’s The Three Doctors, but then when Tom Baker took over as the fourth Doctor in 1974 they became closely associated with them from the end of his very first story Robot onwards. After his departure from the show they appeared or were referred to from time to time – the most recent occasion being when the twelfth Doctor offered Professor Moorhouse one in 2014’s The Mummy On The Orient Express. The Doctor attributes Bill’s continued survival to her having to fight off the Monks’ influence in this year’s The Lie Of The Land. It is also in this story that Bill witnesses the Doctor apparently starting to regenerate, though because he stops before any change occurs she wouldn’t necessarily know what it meant, which may explain her ignorance of it here. He first mentioned regeneration to her in Knock Knock and brushed away the follow-up question, but in The Eaters Of Light he mentions regeneration and she doesn’t bat an eyelid. You can’t retain it The time streams being ‘out of sync’ was a concept formally introduced in The Day Of The Doctor to explain the Doctor’s past selves not being able to remember the events of the story – though obviously previous multi-Doctor stories had generally warranted that the Doctors not know how things were supposed to pan out at the time. There are odd exceptions to this, such as the Master with the dematerialisation circuit in this story, and also the tenth Doctor remembering exactly how to pilot the TARDIS to avoid a catastrophe when he met the fifth Doctor in 2007’s splendid mini-episode Time Crash. The idea of concealed access panels within an otherwise open environment has been seen in Doctor Who before in 1973’s Carnival Of Monsters, in which the Doctor and his companion Jo found themselves inside a ‘MiniScope’, which housed various people, aliens and locations from time and space. Though seeming to be on a ship in the Indian Ocean, the pair realise the truth when they spot a hatch that none of the other characters can see, and use it to escape into the machine. The Cybermen fly here for the second time, having previously been unable to do so until 2014’s Death In Heaven, where they not only destroyed the Doctor’s presidential plane in mid-air but also – at Danny Pink’s command – shot up into the sky to sacrifice themselves and disperse Missy’s Cyber-pollen rain clouds. A few more back-references from earlier in the series: Nardole revealed in Extremis that he had been given full permission to kick the Doctor’s backside by the late River Song – and that he was more than happy to extend that to Bill, should she do anything to put herself in danger. In that same story, it was Nardole who introduced the idea quoted by the Doctor here that good is only truly good when it’s without hope, without witness and without reward. And then of course there’s Bill’s romantic interest Heather from The Pilot, who was taken to pilot an alien vessel and given extraordinary abilities… The idea of the TARDIS being the Doctor’s tomb came up once before, in The Name Of The Doctor back in 2013. On that occasion the Doctor visited said tomb on Trenzalore – the setting for The Time Of The Doctor, which is when the Time Lords helped him avert that particular fate. This is also now the second time in a row that the Doctor has been left believing his companion to be dead after Clara had a last minute stay of execution to travel around the universe with Arya Stark… The unconscious Doctor’s flashbacks are an homage to the end of 1981’s Logopolis, which saw the fourth Doctor near death and being buoyed by images of his companions from the past seven years saying his name. The twelfth Doctor’s flashback goes beyond his own incarnation, and as well as Bill, Nardole and Missy it includes ninth (and tenth) Doctor companions Rose and Captain Jack, tenth Doctor companions Martha and Donna (plus fourth Doctor companion Sarah Jane, who returned to become something of an honorary companion to the tenth), eleventh Doctor companions Amy and Clara, plus recurring allies of the eleventh and twelfth Doctors Madame Vastra, Jenny Flint and River Song. Poor Strax… Another throwback to Logopolis is the tolling of the Cloister Bell, which was introduced in that story as a device to warn the Doctor when the TARDIS senses the gravest of emergencies and has been used liberally by the series thereafter, particularly since its return in 2005. Speaking of the tenth Doctor’s demise, the twelfth has clearly been learning lessons from his predecessor in how not to regenerate – the tenth refused to change until he’d done a farewell tour of all of his companions (And for some reason, Jessica Hynes’ identical granddaughter) in The End Of Time Part 2. It was then revealed in The Sarah Jane Adventures that the Doctor in fact went back and saw everyone he’d ever travelled with between receiving his fatal radiation dose and regenerating in the TARDIS. A quick knockabout with the first Doctor doesn’t seem like that much by comparison… So yes, the return of the first Doctor, played by Harry Potter and Game Of Thrones actor David Bradley, who played William Hartnell in the 2013 Mark Gatiss film An Adventure In Space And Time. This is the second major recasting of the part following 1983’s anniversary special The Five Doctors, where the role was played by Richard Hurndall (with Hartnell having passed away in 1975). Though it is yet to be officially confirmed, the first Doctor’s clothing and dialogue plus the snowy surroundings suggest that the twelfth Doctor has landed at the South Pole in 1986 (But we suspect they might gloss over the latter aspect), where the first Doctor’s body finally ‘wore thin’ and caused his regeneration into the second – following his first encounter with the Mondasian Cybermen in The Tenth Planet. At the end of that adventure, the Doctor announces he must return immediately to the TARDIS, and dashes off ahead of his companions Ben and Polly. By the time they get to the TARDIS the Doctor is ready to change, but we suspect we’ll be finding out what happened in those missing minutes on December 25th… See you at Christmas, folks.