C is for... Cyber Leader

As the name suggests, this is the commander of a unit of Cybermen. They are distinguishable from their troops by having black markings on their helmets. The first Cyber Leader we, and the Doctor, encountered, led a party who were survivors of a war between themselves and Earth forces. The upper part of his helmet, including the "ear muffs" and handles were black. The Cyber Leader was about to launch an attack on the remains of the planet Voga, which had supplied gold to the humans during the war. He had made contact with a man named Kelner, who was stationed on a navigation beacon orbiting Voga, which had drifted into the solar system and been captured by Jupiter's gravity. At this point in their history, the Cybermen were scattered in small groups across the cosmos. The Leader wanted to destroy Voga before creating a new Cyber army. Kelner was a double agent, however, being paid by the Vogan leader Vorus to lure the Cybermen onto the beacon so they could be destroyed by a rocket he had commissioned. An attempt to destroy Voga using bombs carried to its heart was foiled, and the Leader initiated a back-up plan - to fill the beacon with more bombs and send it crashing into the asteroid. This plan was also defeated, and the Leader was aboard his spaceship when it was hit by the Vogan rocket.
This Cyber Leader exhibited many emotional traits, suggesting that their depleted army had limited supplies, and so full conversion had not taken place.

The next time the Doctor met a Cyber Leader, he had a very similar plan to his predecessor. This time it was the Earth which was to be destroyed with a bomb - as the Cybermen wanted to prevent the humans from forming an alliance against them. This Cyber Leader had black handles on his helmet, but was otherwise indistinguishable from his underlings. Again the Leader had a back-up plan - the same plan actually - except this time it was a space freighter that would be loaded with bombs and crashed into the planet. The Leader claimed to have met the Doctor before, though not in this incarnation. This suggested that a Cyber Leader's memories are somehow downloaded and placed into another Cyberman. The Leader took over the freighter with his troops and set about aiming it at the Earth. He decided to observe the destruction of the planet from the TARDIS, and threatened Tegan in order to force the Doctor's compliance. Adric was left aboard the spaceship. His tampering with the Cyberman control system caused the freighter to travel back in time some 65 million years, and the Doctor was able to inform the Leader that his actions had helped to create the human race, rather than wipe it out. The Leader was destroyed when the Doctor ground Adric's gold badge into his chest unit, suffocating him.

When all five Doctors and a number of their companions were abducted to the Death Zone on Gallifrey they encountered several Cyberman units. At least two Cyber Leaders were present, as one was seen to perish at the hands of a Raston Warrior Robot, and another was led with his troops into a trap in the Dark Tower by the Master.

Another Cyber Leader was despatched to Earth in 1985, setting up bases on the dark side of the Moon and in the sewer system beneath London in readiness for the arrival of Mondas the following year. The Cyber Controller on Telos intended to pervert the course of history by using a time vessel to prevent Mondas' destruction. The Leader captured the alien mercenary Lytton, and later the Doctor and his TARDIS. He then forced the Doctor to take them all to Telos in the TARDIS by threatening Peri's life. This Leader was destroyed by the Doctor in Cyber Control, shot by a Cyber weapon.

A Cyber Leader then led a scout party to Earth in 1988 to obtain the Nemesis statue, which was composed of a living metal developed as a weapon on Gallifrey. The Cybermen had a massive fleet hidden in orbit above the planet, ready to turn Earth into New Mondas. The Doctor appeared to give the Leader control over the statue, but it flew into the heart of the fleet and destroyed it. The Leader was then killed by Richard Maynarde, Lady Peinforte's manservant, using one of her gold-tipped arrows.

The Cybermen created on the parallel Earth by the Cybus Corporation also adopted a Cyber Leader role, again using black handles on the helmet to identify their rank. The Leader which took over Torchwood Tower broadcast their demands for surrender to the entire world. It could not understand why the humans resisted them. Later, it tried to form an alliance with the Daleks, but they refused. Here it was confirmed that when a Leader was killed, its function was downloaded into another unit which became the new Leader.

A new form of Cyber Leader was seen when a group of Cybus Cybermen escaped from the Void to Victorian London. This one had a black face plate as well as black handlebars on its helmet, and its brain case was transparent. It wanted to create the Cyber King, using a woman named Miss Hartigan harnessed to a Dreadnought Class cybership. She rebelled against their mental control and destroyed the Leader, disintegrating him with her new powers.
This same design of Cyber Leader was seen in command of the 12th Cyber Legion, encountered by Rory Williams when he went in search of his abducted wife Amy.
The latest incarnation of the Cybermen have yet to sport a designated Cyber Leader.

Played by: Christopher Robbie, David Banks, Paul Kasey, and voiced by Nicholas Briggs. Appearances: Revenge of the Cybermen (1975), Earthshock (1982), The Five Doctors (1983), Attack of the Cybermen (1985), Silver Nemesis (1988), Doomsday (2006), The Next Doctor (2008), A Good Man Goes To War (2011).

• Robbie played the Cyber Leader in Revenge - the first time that the actors in the costumes voiced them. Banks then played the Leader from Earthshock to Silver Nemesis. Since the series returned, Kasey has played the Leaders in costume, with Briggs providing the voices.

C is for... Cyber King

When a group of Cybus Cybermen escaped from the Void, using stolen Dalek technology, they found themselves stranded in Victorian London with little resources. They made contact with a woman named Miss Hartigan, who worked in a local poorhouse for the city's destitute children. She agreed to help them create the Cyber King. This was a gigantic machine shaped like a Cyberman but driven by steam power. Within was contained a full cyber-conversion factory. Children from a number of workhouses were used as slave labour to help with its construction. It required a controlling unit, and Miss Hartigan was shocked to discover that she was intended to become this. However, her strong will refused to allow her to be totally enslaved to the machine. She destroyed the Cyber Leader and took over, launching the machine on an attack on the city. The Doctor recognised it as a Dreadnought Class Cyberman craft.

The Cyber King had risen out of the Thames where it had been constructed and began firing on the city below. The Doctor took to a balloon to confront Miss Hartigan. He was able to show her that she had become a monster and the cyber-conditioning was broken. She perished - taking the Cybermen with her. The Doctor then used the Dalek device which had brought them here to open a portal into the Void. The collapsing Cyber King fell into this.
The Doctor was puzzled as to why this event was never later remembered. It transpired that the whole thing was deleted from history when the universe was rebooted by the Pandorica.

Played by: Dervla Kirwan (Miss Hartigan). Appearances: The Next Doctor (2008).

C is for... Cyber Controller

The leader of the Cyberman race, who was based on the planet Telos. This became the home of the Cybermen after their original homeworld of Mondas was destroyed. The Controller was distinguishable from the rest of his kind as he was taller, had no chest unit, and his helmet had a much larger cranium, with no side handles. The cranium case glowed, and the Controller's increased brain could be seen within it. Both helmet and body were of a darker hue than the other Cybermen.
As their resources were running low, the Controller had ordered that all Cybermen on the planet should put themselves into cryogenic suspension. He took up a position in a sealed chamber on his own, behind a large stylised relief of a Cyberman head. Their tomb complex was rigged with booby-traps, and the Controller hoped to convert any explorers who came looking for them.
Once reanimated by the Logician Eric Klieg, the Controller ordered the servant of Klieg's partner, Kaftan, to be partially converted, and deployed Cybermats to attack the archaeological expedition after they had escaped back to the upper levels and sealed off the tomb area. Klieg allowed the Controller to come up to the surface with the servant - Toberman - as he wanted to strike a deal with the Cybermen. The Controller first had to recharge himself, and an attempt to lock him in the recharge unit by the Doctor failed when he smashed his way out. He had mental control over Toberman and ordered him to attack Klieg, and then killed Kaftan when she shot at him. The Doctor used Toberman's previous loyalty towards his mistress to turn him against the Controller and he attacked him. The Doctor had the tombs evacuated and set about electrocuting the main doors. The Controller tried to break out, but Toberman closed the doors - forming the electrical circuit. This killed the servant, and apparently destroyed the Controller.

However, on the Doctor's subsequent visit to Telos, now in his sixth incarnation, he discovered that the Controller had survived. His body had been upgraded to a similar form as his underlings, but he was still taller and retained the larger cranium, without side handles to the helmet. He was working on a plan to prevent the destruction of Mondas using a captured time vessel. He knew of a plot to steal this but allowed the attempt to proceed as it would make for an interesting psychological experiment. The surface of Telos was also being mined with the highly volatile mineral vastial, as the Controller wanted to observe the destruction of the planet once they were ready to return to Mondas.
In Cyber Control, the mercenary Lytton, who had been in league with the Cryons - Telos' native species - stabbed the Controller in the arm, allowing the Doctor to then shoot and destroy him with a Cyberman weapon. Cyber Control was then blown up with a supply of vastial, along with the time vessel.

When a new race of Cybermen were created on a parallel Earth, their creator - industrialist John Lumic - was selected to become their Cyber Controller. He resisted conversion, wishing to remain human for a while longer, but his life support system was sabotaged by his lackey Mr Crane, and the Cybermen proceeded with the conversion to save his life. He was distinguishable from the other Cybermen by having an exposed brain case, glowing eyes, and a number of cables bolted to his torso, attaching him to his throne-like chair. When their emotional inhibitors were sabotaged, wrecking his Cyberman army, the Controller was unaffected. He was able to leave his chair, disconnecting the cables, in order to pursue the Doctor and his friends. They were fleeing in Lumic's own zeppelin, and the Controller began to climb up after them. Pete Tyler used the Doctor's sonic screwdriver to burn the rope ladder he was ascending, and he plummeted to his death in the exploding conversion factory.
A group of Cybermen who had been trapped for centuries in their crashed spaceship beneath the Essex town of Colchester attempted to create a new Controller by converting the Doctor's friend Craig Owens, but his love for his son allowed him to resist the process.

The Lumic Controller at the DW Experience in 2017.

Played by: Michael Kilgarriff and Paul Kasey. Voiced by Peter Hawkins, Michael Kilgarriff, Roger Lloyd-Pack. Appearances: Tomb of the Cybermen (1967), Attack of the Cybermen (1985), The Age of Steel (2006).

• Kilgarriff played the Controller in both of the two classic series appearances, though he was voiced by regular Cyberman vocal artist Hawkins in the first story. Regular monster performer Kasey was in the costume of the Controller in the 2006 story, whilst Lumic actor Lloyd-Pack provided the voice.

C s for... Cutler, General

General Cutler was the hard-nosed commander of the Snowcap space tracking station, which had been established at the South Pole. He demanded hard work and loyalty from the men who served under him - a mix of military personnel and civilian scientists. He was deeply suspicious when the Doctor and his companions Ben and Polly turned up outside the base, just after the latest space mission, Zeus IV, had begun to experience problems. Soon after, a new planet was seen to drift into the solar system close to the Earth. The Doctor tried to warn the General of the consequences of this, but he failed to heed his advice. The base was attacked and taken over by Cybermen from the new planet - Mondas.
After the initial assault had been overcome, Cutler discovered that his son had just been sent up in Zeus V to investigate Mondas and to try to help the earlier mission. Cutler began to lose his reason, becoming determined to save his son at any cost. He wanted to deploy the Z-Bomb which was housed at Snowcap, even though his scientists warned that this could devastate the Earth as well. When refused permission to use it, he went ahead anyway. Ben was able to sabotage the missile before it could be launched. Cutler would have turned on him and his friends had the Cybermen not broken back into the base and killed the General.

Played by: Robert Beatty. Appearances: The Tenth Planet (1966).

• Beatty was Canadian, but he cornered the market in American characters in TV and film in Britain for more than three decades. Based in London during WWII, he broadcast radio reports about the Blitz to listeners in the US and Canada. He played the fictional US President in the fourth Christopher Reeve Superman movie, and portrayed two real Presidents - Truman and Reagan.

C is for... Curbishley

Colonel Hugh Curbishley was the husband of Lady Eddison, who in December 1926 had invited the crime writer Agatha Christie to her home for the weekend. Sir Hugh was confined to a wheelchair. He was working on his military memoirs, though could often be sidetracked by memories of seeing the can-can dancers in Paris in his youth.
He and Lady Eddison had a son named Roger, who was their sole heir. He was gay, carrying on a secret relationship with one of the valets - Davenport. The Doctor and Donna Noble crashed the party, and stayed on to help investigate the murder of family friend Prof. Peach - struck down by a piece of lead piping in the library. He had been researching the family's history.

At dinner that night, Roger was also killed during the sudden appearance of a huge wasp-like creature. The killer proved to be the local vicar - Arnold Golighlty. He was Lady Eddison's illegitimate son, hence Roger's own step-brother, whose father had been an alien Vespiform.
Suspecting that his secret was about to be revealed by the Doctor and Mrs Christie, Sir Hugh admitted that he was not really an invalid. He had been feigning his disability as he was scared that his wife might leave him.

Played by: Christopher Benjamin (Sir Hugh), and Adam Rayner (Roger). Appearances: The Unicorn and the Wasp (2008).

• Benjamin had appeared in the programme twice before - first as Sir Keith Gold in Inferno, and more famously as music hall impresario Henry Gordon Jago in The Talons of Weng-Chiang - a role he has revisited many times on audio.
• Rayner recently starred in Tyrant and was cast as the new Saint - Simon Templer - in a pilot exec produced by the late Sir Roger Moore which failed to make it to series.

Inspirations - The Abominable Snowmen

A fairly straightforward one this, as this is Doctor Who's first real foray into the realms of cryptozoology. This is the study of animals which have yet to be recognised by science, including the search for new species or ones previously thought extinct. Species become endangered, or die out altogether, but each year new ones are discovered - sometimes hidden in plain sight, such as when an animal, bird or insect previously thought to belong to a known group is found to have its own unique genetic fingerprint. The monthly publication Fortean Times has a regular column on the subject. Cryptozoology also covers the search for creatures which have attained mythical status. These include sea serpents, giant squid, lake monsters and large ape-like men such as Bigfoot. One of the other famous ones, Bigfoot's Himalayan cousin, is the Yeti, or Abominable Snowman.
This six-part adventure gives the Yeti a Sci-Fi spin - presenting them as robots in disguise, servants of an alien intelligence - before revealing at the conclusion that the creatures really do exist.

The Abominable Snowmen is written by Mervyn Haisman and Henry Lincoln. Lincoln had been an actor - under the name Henry Soskin. He had an interest in history, especially its more occult margins. Lincoln will later become obsessed with the mystery surrounding the small French town of Rennes-le-Chateau. He would collaborate on the book The Holy Blood and the Holy Grail, which formed the basis for the Dan Brown comedy The Da Vinci Code. (Well I found it a hilarious read). When called upon to play a part in a play about Ancient Egypt, he took exception to the lack of research from the author and agreed to make it more realistic. Thinking he could do better, he started his own writing career and soon paired up with Haisman. Haisman had also been an actor.
Both seemed to have been inspired in writing their first contribution to the series after viewing a Sunday Night Theatre presentation on the BBC back in 1955. This was called The Creature, and it was written by Nigel Kneale. It starred Peter Cushing as a Himalayan explorer searching for the Yeti.
You may well have seen the Hammer film adaptation, also starring Cushing, which went under the title The Abominable Snowman. As well as Cushing, both versions feature the actor Wolfe Morris, playing a Tibetan mountain guide. He features in the Doctor Who story as the Master of Detsen monastery, Padmasambhava.
The TV play and movie feature a Master of a local monastery who seems to have supernatural powers and can commune in some way with the titular creatures. Kneale's Yeti prove to be an ancient human offshoot, who are wise and gentle, and Kneale posits that they will become the future of the human race as well, after we have wiped ourselves out.

The Yeti, or Meh-Teh, is supposed to inhabit the Himalayas of Nepal, Bhutan and Tibet. It is said to be huge furry creature which walks upright like a man. It appears in ancient Buddhist writings. If it exists at all, many scientists think it is simply a type of bear, whilst believers think it is a missing link ape-man. Stories about the creatures first arrived in the west during the 19th Century, when the region began to open itself up to mountaineers, plant-hunters and other explorers. The term "Abominable Snowman" was first coined in 1921, by the British Everest Expedition. The party discovered strange animal tracks which their Sherpas claimed belonged to the Wild Man of the Snows. The "Abominable" part of the name derives from a mistranslation of the Tibetan word Metoh. It should mean "man-bear" but a newspaperman translated it as "filthy" - hence abominable.
Interest peaked in 1951 when that year's Everest expedition encountered a huge footprint, which was photographed with an ice-pick to show the scale.

As with the Nigel Kneale storyline, Haisman and Lincoln feature a British explorer in their tale. This is Edward Travers, who has come specifically to hunt for the creatures. He suspects the Doctor of belonging to a rival expedition. The Abominable Snowmen is one of those stories which relates to an unscreened adventure, as the Doctor claims to have visited Detsen in the 16th Century and helped the monks fend off bandit attacks. He has a sacred relic in his possession - a small bell known as the ghanta - which he took for safekeeping, and now plans to return. A ghanta is actually a ritual bell used in Hindu ceremonies.
The writers then populate their monastery with a number of characters, some of whose names derive from Buddhism. Padmasambhava was an Indian mystic - also known as Guru Rinpoche - who brought a form of Buddhism to Tibet in the 8th Century, during the reign of King Trisong Detsen. Khri-song Deutsen was another name for him. He gives his name to the leader of the warrior monks, pledged to protect the monastery. The younger monk - Thonmi - gets his name from Thonmi Sambhota, a Tibetan writer, credited with devising the Tibetan alphabet in the 7th Century.
Ralpachan was another king, as was Songtsen Gampo.

When it came to novelising this story in the 1970's for Target, writer Terrance Dicks was asked by his boss to slightly amend the names of the Tibetan characters. The boss in question was Doctor Who's producer Barry Letts, who was a practicing Buddhist, and he felt that it was disrespectful to name character after real people important to his philosophy. Dicks simply moved a single letter in each case, or added / removed a hyphen.
In closing, we should take the opportunity here to mention that this story marks the beginning of the great UNIT dating controversy. This story is categorically said to take place in 1935, so all subsequent datings mentioned by Professor Travers, and by the Brigadier thereafter, have to start from this point.
Next time: More icy escapades, as the Doctor and his companions encounter not-so-little green men from Mars...

Story 188 - The Sound of Drums / Last of the Time Lords

In which the Doctor and his companions escape from the planet Malcassairo using Jack's Vortex Manipulator. They find themselves in present day London. The Doctor explains that he fused the TARDIS controls so that it could only travel between its last two destinations - present day Earth and the year 100 Trillion. The Master could have arrived six months or so ago, however. Martha realises they have just missed the General Election, and they see a TV screen showing the new Prime Minister and his wife. She suddenly realises where she had heard the Master's voice before - he is Harold Saxon, the new PM. The Doctor and Jack accompany Martha to her flat, where the Doctor tries to work out how the Master could have achieved this coup. Before the election he had been responsible for the Archangel Network of communications satellites, and the Doctor realises that he has used these to send out a hypnotic signal. At the newly re-built Downing Street, the Master holds his first cabinet meeting - at which he promptly murders everyone in attendance with poison gas. Martha's sister Tish has suddenly found herself working for Mr Saxon. A journalist named Vivien Rook meets with Mrs Saxon - Lucy - and tries to convince her that her husband's biographical details are a lie. He has invented an entire history for himself yet only appeared a few months ago. The Master arrives, along with a metal sphere which materialises out of thin air. The sphere attacks and kills Rook.

The Master then makes a TV broadcast, hinting that he knows the Doctor and his friends have arrived, and tells the world that he has made first contact with a race of aliens called the Toclafane, who will arrive the following morning. They find that a bomb has been placed in the flat and escape seconds before it explodes. Martha fears for her family's safety and insists on going to her mother's home. When they arrive, her father urges them to run whilst they can, and they see him and Francine being bundled into the back of a van by armed police. Tish is also arrested at Downing Street. Martha is able to warn her brother Leo to go into hiding with his family. The Doctor, Martha and Jack go on the run. Their faces are shown on TV as wanted criminals. Martha then receives a phone call from the Master, which the Doctor takes. The two discuss previous meetings, and the Master asks about the outcome of the Time War. He reveals that the Time Lords had resurrected him to fight, but he had fled and hidden himself in human form. The Doctor asks him about the Toclafane, as he knows these were creatures from nursery stories on Gallifrey, but the Master refuses to tell him anything, and informs them they will be hunted down. They take refuge in an abandoned building, where the Doctor tells his companions of the Master's history back on Gallifrey - of how children had to face the Untempered Schism. This was a hole in space / time. Some ran away from it, and others went mad. The Doctor did the former, whilst the latter may have happened to the Master.

Each of them has a key to the TARDIS which has perception filter properties. The Doctor adapts these to allow them to move around. They go to an airbase where the President of the United States is due to land. He is furious that the British PM has initiated first contact unilaterally and insists that the UN takes over. They see Martha's family being forced onto a plane which is taking everyone to the UNIT ship Valiant. The Doctor and his companions follow using the Manipulator, and find that the ship is a sky base. The Doctor finds the TARDIS here - cannibalised to become a Paradox Engine. The time for the Toclafane to arrive approaches. A group of spheres appear. The President tries to take control of the situation, but they obey only the Master. The world watches in horror as the President is killed. The Master uses his laser screwdriver to incapacitate the Doctor and to kill Jack. He has the Doctor's hand, giving him the Doctor's DNA. Coupled with technology developed by Professor Lazarus, he uses his screwdriver to cause the Doctor to age greatly, his ability to regenerate suspended. The Doctor whispers a message to Martha then she departs using the Manipulator. The Paradox Engine is activated and the sky splits open - forming a bridge to the far future. Millions of Toclafane emerge and are sent to decimate the Earth's population. Martha looks on helplessly as London is attacked...

One year later, the Master rules the Earth from his base in the sky. Toclafane patrol everywhere, killing for pleasure. Whole countries have been destroyed and the Master has begun to build a vast war fleet. He aims to turn the Earth into the new Gallifrey and launch a war throughout the cosmos. Lucy is a shadow of her former self, having suffered continual abuse at the hands of her husband. An escape attempt by the Doctor, Jack and Martha's family fails. She, meanwhile, has been travelling the planet and it is rumoured that she has found a means of stopping the Master. She arrives back in England where she is met by a doctor named Tom Milligan, who is going to help her. Milligan takes her to meet a scientist named Professor Docherty. Martha reveals that she has found a way of disabling a Toclafane, after one was brought down by an electrical storm in South Africa. The Master makes a TV broadcast, directed at Martha. He uses his laser screwdriver to harm the Doctor further - aging him even more so that he ends up a tiny wizened creature. Martha, Tom and Docherty manage to bring down a Toclafane and open up its casing - hoping to learn more about them so that some weakness might be found. Within is a human head with cybernetic implants. The creatures are what the future human race will become, the inhabitants of Utopia in the year 100 Trillion. The Doctor had worked this out. The Paradox Engine has allowed them to travel back and destroy their own ancestors.

Martha claims to have a weapon which comprises three chemicals which can kill a Time Lord. She has come to Britain to obtain the third of these. Docherty's son is a captive of the Toclafane, and she informs the Master of Martha's plan to get him released. At a house in South London, Martha tells the slave workers about the Doctor. She is then captured by the Master, who kills Tom. On the Valiant, the Master is getting ready to launch his war fleet. Martha's family and Jack are brought to the bridge to witness her execution. However, Martha refuses to take the Master seriously. The Doctor points out that he would never have asked Martha to use a weapon. She had known that Docherty would betray her, so that she would be here in this place at this time. Her travels across the globe have been to tell the people about the Doctor, and they have all been urged to think about him at the point when the missiles are to be launched. The Doctor, meanwhile, has mentally tuned himself into the Archangel Network. As everyone on the planet thinks about him, he is returned to normal, harnessing all the mental power. The Master flees to the surface, determined to blow up the rockets - but the Doctor knows he would never commit suicide. They return to the Valiant as Jack destroys the Paradox Engine. Time is thrown backwards to the moment when it was first activated, though everyone on the ship is immune to this effect. The Doctor intends to keep the Master prisoner in the TARDIS, but Lucy shoots him. He refuses to regenerate and dies. The Doctor burns his body, but later someone finds and removes his signet ring. Jack is taken to Cardiff to be reunited with his Torchwood team. As he walks away, he hints that he might eventually become the Face of Boe... Martha decides she must stay behind and look after her traumatised family. She has held romantic feelings for the Doctor and knows they will never be reciprocated.
The Doctor leaves alone, but a short time later the TARDIS collides with a vessel - the Titanic...

The Sound of Drums / Last of the Time Lords were written by Russell T Davies, and were first broadcast on 23rd and 30th June, 2007. They mark the finale of the third series, and see the departure of Martha Jones as the regular companion.
For fans of the show, one moment of the first half stands out as the Doctor reminisces about Gallifrey. We see the planet for the first time in the new series, including the Citadel of the Time Lords which we had never seen the exterior of before. The young Master wears black and white robes akin to those sported by the Time Lords in their very first appearance - at the Doctor's trial in the final episode of The War Games. Other adult Time Lords wear the costumes first designed by James Acheson for The Deadly Assassin. The Seal of Rassilon makes its first appearance since the TV Movie. For the first time on screen we see a black Time Lord - though Big Finish had featured a black incarnation of Rassilon a few years before.
As mentioned before, many see these episodes as the second and third parts of a trilogy, but RTD himself tended to think of them as a separate two part finale.
There are lots of references to previous stories - not just to this series' arc. The Master watches Teletubbies on TV - a nod to the scene in The Sea Devils where his earlier incarnation had viewed an episode of The Clangers. The rebuilding of Downing Street goes back to its destruction in World War Three, and the whole election of Mr Saxon owes its origins to the Doctor's breaking of Harriet Jones in The Christmas Invasion. The severed hand of the Doctor from that episode also comes into play, coupled with references to the work of Prof Lazarus in The Lazarus Experiment, where it had been stated that he was being funded by Harold Saxon.

The alias adopted by the Master is as Olde English as you can get - hinting at King Harold Godwinson and the Anglo-Saxons of the country before the Norman invasion. He gains his own companion - wife Lucy - just as the Doctor has always had companions, though this being the Master he cruelly abuses her. He is also seen to favour jelly babies.
The Toclafane derive from a monster idea from the 2005 series. Had the production team been unable to secure the use of the Daleks, then these would have been their replacements.
John Simm is obviously the main guest artist as the Master. Joining him are Alexandra Moen as Lucy, Tom Ellis as Tom Milligan, Ellie Haddington as Prof Docherty, and Nichola McAuliffe as Vivien Rook. Colin Stinton portrays the US President, Winters. Elize Du Toit returns as the sinister woman" last seen in 42.

A party political broadcast for Saxon features cameos from the band McFly, Sharon Osbourne, and former MP Ann Widdecombe.
Adjoa Andoh will return in the following series as Francine Jones, but this is the last appearance for Trevor Laird as dad Clive, Gugu Mbatha-Raw as sister Tish, and Reggie Yates as brother Leo. The latter features only briefly in the first half.
For the story arc points - see above. The cliffhanger sees the Toclafane descend on the planet to decimate the population, as the elderly Doctor is forced to watch, whilst Martha observes the carnage from a hill overlooking London.

Overall, a great story in which the Master actually gets to rule the world for a change. Jack is woefully underused, and even David Tennant is largely absent for the second half  - though this does allow Freema Agyeman a far bigger role to play. As with all RTD finales, the conclusion depends on a great big Deus Ex Machina, and this one is particularly overblown as the Doctor gains god-like powers.
Things you might like to know:

• The boy Master is played by William Hughes, who had played the young Casanova in the RTD penned series starring David Tennant, just before he got called up for TARDIS duties.
• Vivien Rook appears to have been named in reference to veteran journalist Jean Rook, who had once written an article attacking Doctor Who for being too scary for children.
• Jack's claim to have been called the Face of Boe as a young man, as he was used as a poster boy for the Time Agency, seems to hint that he will eventually evolve into the big head in the glass jar as seen in the first three seasons. This is not necessarily the case. He might have known about the Face and that the Doctor and Martha had met him, and was just pulling their legs.
• When the Master broadcasts to the planet just after the death of President Winters, he paraphrases the same opening as his earlier self when broadcasting his demands in Part Four of Logopolis - "Peoples of the Universe. Please attend carefully...".
• The Time Lord collars were originals - borrowed from the Doctor Who exhibition at Blackpool. David Tennant made sure he got photographed wearing full Time Lord regalia, as the Gallifrey scenes were shot at the same time as the climactic scene of the Doctor and Master confronting each other over the detonation of the missiles.
• Martha's TV was built by Magpie Electricals - a company which surprisingly survived the events of The Idiot's Lantern.
• Winters actually refers to himself only as President-Elect, which would set this story firmly in the middle of winter if the US election was a conventional one.
• He mentions that the First Contact protocol dates back to 1968, which is when The Invasion was broadcast (and took place, depending on your views on UNIT dating).
• One of the Toclafane voices is provided by Zoe Thorne, who had featured as the Gelth in The Unquiet Dead.
• RTD joked that the female hand seen picking up the Master's signet ring at the end belonged to the Rani. The hand actually belonged to production manager Tracie Simpson.
• It had been planned to show the final episode on a big screen in Trafalgar Square as part of the LGBT Pride celebrations, and Freema Agyeman and John Barrowman were in attendance, but a recent terrorist action prevented this taking place.
• As soon as the final episode was broadcast, it was announced that Martha Jones would return for a trio of stories in the second season of Torchwood. Then she will be working for UNIT, and will be engaged to Tom Milligan.
• Before the cliffhanger of the Titanic smashing into the TARDIS is resolved, we have the Time Crash Children In Need sequence to insert.