The Next Doctor
AIR DATE: December 25, 2008
VILLIANS: Mercy Hartigan, Cyber Leader, Cyber King, Cybershades
ALIENS/ MONSTERS: Cybermen, Cybershades
OTHER CHARACTERS: Jackson Lake(the other doctor), Rosita
LOCATION: London 1851
The Doctor lands in London on Christmas Eve, 1851, where he encounters a woman called Rosita who does not believe his claims to be the Doctor she is calling for. Another man, calling himself 'The Doctor' races forward and produces a device he refers to as a sonic screwdriver. A strange creature, with a bronze face like that of a Cyberman but a hunched and furred body, bursts into the alley. The three give chase, but the creature eludes them. In the aftermath of the chase, the two Doctors talk: the Tenth Doctor believes the other to be his next regeneration, but unfortunately the other (dubbed 'the Next Doctor') doesn't recognise him; the Next Doctor explains that many of the memories are missing, and that he cannot remember anything 'since the Cybermen'.
Nearby, a group of Cyberman observe the footage gleaned from a Cybershade (the creature pursued by the trio); however, the Cyberman recognise the Next Doctor, not the original, as their foe. They discuss their plans for the next attack with their ally, Miss Mercy Hartigan. The attack is scheduled for 14:00 hours - the same time as a funeral whose procession the Next Doctor and Rosita observe.
While the funeral takes place, the two Doctors are investigating the house of the deceased, Reverend Aubrey Fairchild. As they investigate, the Next Doctor explains that the Cybermen's presence is linked to a number of murders and child abductions across London, culminating in the Reverend's death. The Next Doctor begins to show signs of remembering the original Doctor, but before he can delve further, the Tenth Doctor finds, hidden in a roll-top desk, a pair of 'infostamps': devices that allow the storage of large amounts of information. The Doctor activates one, discovering it contains information on the history of London from 1066 to 1851.
The Doctor realises the Cybermen have been using the infostamps to update their knowledge of history: however, the Next Doctor remembers he was holding an infostamp the night he lost his memory, which he also remembers to be the night he regenerated. However, the Cybermen attack the house as the Doctors continue the search: the original Doctor fends them off with a cutlass, but the Cybermen are not interested in him - only the Next Doctor. Before they can kill the pair, the Next Doctor activates an electrical charge in the infostamp, destroying the Cybermen.
At the funeral, Miss Hartigan arrives, with a platoon of Cybermen and Cybershades in tow. She spares a number of the mourners (who are owners of workhouses and orphanages), but the others are 'deleted' by the Cybermen. The survivors are fitted with Ear-Pods and dispatched by Miss Hartigan. The two Doctors return to the Next Doctor's home base, where Rosita and the Next Doctor show the original Doctor his TARDIS - a hot-air balloon. The Doctor tells the Next Doctor he can explain what happened to him, which the Next Doctor agrees to. The original Doctor tells him and Rosita about the Battle of Canary Wharf and how the Cybermen were cast into the Void.
However, they managed to escape from the Void when the walls of the universe were weakened in "a greater battle", and came upon a man, Jackson Lake, a mathematics teacher and the first person to disappear. The Cybermen attacked his home and killed his wife. In desperation, Lake grabbed an infostamp to defend himself, one containing information on the Doctor gleaned from the Daleks; though the infostamp destroyed the Cybermen, it backfired, overwhelmed Lake's mind and in his fear and despair, he came to believe he was the Doctor. The Doctor gives him proof of this: the fob watch the Next Doctor carries with him is engraved with the initials JL. Lake, remembering who he is, is overcome.
Meanwhile, the converted workhouse owners are marching the children of their establishments through a sluice gate to the Thames, which they discover is guarded by Cybermen and Cybershades. The Doctor and Rosita go to investigate and are confronted by Miss Hartigan. She explains she has not been converted, and the Cybermen offered her her liberation. The Doctor returns the infostamp to the Cybermen, who download it, confirming he is their foe, not Lake. Miss Hartigan explains that the children are a workforce, to bring about the birth of 'it', but refuses to say what. She orders the Cybermen to delete the pair, but Lake provides a distraction with another infostamp and they are able to escape. Miss Hartigan furiously announces that 'the CyberKing will rise tonight!'
Lake tells the Doctor he and his family were moving to London so he could take up a teaching post. The Doctor realises there may be a way into the Cybermen's base through Lake's house. Inside the house, they find a Dimension Vault; a piece of technology stolen from the Daleks that allowed the Cybermen to escape the Void. In the Cybermen's base, the captive children are put to work generating power to allow the 'Ascension of the Cyberking'.
However, in the throne chamber, Hartigan is told by the Cyberleader that she will be the Cyberking, not the Cyberleader as she assumed. The Cyberleader explains that by becoming Cyberking, Hartigan will receive her liberation from the anger, hatred and rage in her mind. However, Hartigan proves too powerful; her mind is too powerful to control, and she uses her new powers to obliterate the Cyberleader when it tries to intervene.
The Doctor, Rosita and Jackson infiltrate the Cybermen's base: the Doctor realises that when the machine reaches 100% power, the children will be disposed of. The trio evacuate the children, including Jackson's son, who was abducted by the Cybermen the night they attacked his house, who was the last thing Lake couldn't remember, the reason he wanted to forget everything and think he was the Next Doctor. However, the Cyberking - a Dreadnought-class ship containing a cyber-conversion factory onboard - emerges from the Thames, commanded by Hartigan and an army of Cybermen, and begins to lay waste to London. After sending Rosita and Jackson to safety, the Doctor commandeers the hot-air balloon and rises to the top of the Cyberking.
He offers Hartigan a deal: to take her to a place where she and the Cybermen can live in peace. She refuses, and the Doctor attacks her with the infostamps. Though Hartigan initially taunts him for failing to kill her, the Doctor replies that wasn't his intent: instead he has severed her connection from the Cyberking, setting her free. Hartigan, realising what she has become, screams in horror as the broken connection destroys her and the Cybermen, before causing the Cyberking to begin to self-destruct. However, before it can topple on the crowds below, the Doctor uses the Dimension Vault to transport the Cyberking into the Time Vortex, where it will be harmlessly destroyed.
In the aftermath, Jackson thanks the Doctor for what he has done and offers him a place at his Christmas celebration with Rosita and his son. The Doctor initially refuses, but ultimately reconsiders. The Doctor offers Jackson a look inside the TARDIS, and he becomes overwhelmed by amazement. He again thanks the Doctor, but points out that in all the information he saw, the Doctor had companions present. The Doctor explains that in the end, they all leave, for a variety of reasons, and that ultimately, they break his heart. This is the only time in the whole episode we see how hard losing Donna has been on him. The Doctor then tells Jackson that, of all the people who could have been him, he was glad it was Jackson. They leave together, to celebrate Christmas.