David Tennant as the Edwardian John Smith
In Paul Cornell's fabulous two-parter "Human Nature" / "The Family of Blood" (adapted from his very popular and critically acclaimed novel
Human Nature), David Tennant's Tenth Doctor and his companion Martha Jones find themselves in 1913 England on the run from The Family Of Blood, a small group of aliens who exist in a green gaseous form until they possess human bodies. For their escape to work, the Doctor uses a Chameleon Arch to hide his Time Lord essence in a fob watch and becomes an ordinary human. He becomes a school teacher named John Smith and finds employment teaching history (appropriately enough for a person so familiar with all of history) at a private school.
Martha meanwhile finds work at the school as a maid and does her best to keep an eye on the Doctor (not easy, since he doesn't actually remember who she is) and waits for the time when the Family Of Blood will die as their life spans are short; she and the Doctor don't expect to be at the school for more than three months (when the story opens, it's November and they've been at the school for 2 months already). Once the Family dies, Martha will open the watch and the Doctor's Time Lord essence will be returned allowing him to become the Doctor once more. Unfortunately for Martha, an unusual boy named Tim Latimer (played brilliantly and beautifully by Thomas Sangster of
Love Actually and
Nanny McPhee fame) takes the watch from John Smith's mantle shelf when he's in Smith's office to collect a book, and opens it. He releases some of the Doctor's memories and allows the Family Of Blood (who've arrived in the area by this time and begun to inhabit various members of the surrounding community and one of the students, Jeremy Baines) to scent out the Time Lord essence contained in the watch.
Unfortunately, John Smith has begun a relationship with Matron Joan Redfern (Jessica Hynes nee Stevenson), the school nurse, to whom John Smith shows his Journal of Impossible Things - a record of his dreams of his life as the Doctor, though he doesn't know that's what his dreams are about.
A page from The Journal of Impossible Things
showing all ten incarnations of the Doctor.
(Left hand page: Ten and Nine;
Right hand page, left to right, top to bottom:
Four, Three, Two, Seven, Eight, One, Six, Five)
The first episode ends with the four members of the Family arriving at the November 11 village dance to persuade John Smith to turn back into the Doctor as they want his Time Lord biodata to allow them to survive beyond their usual short lifespans. The cliff-hanger ending of the episode sees Baines insisting that John Smith turn back into the Doctor or choose between who will die - his friend (Martha) or his lover (Joan). Since John Smith isn't the Doctor, it's up to Martha to get them out of this impossible situation, which she does by executing a nifty move that allows her to claim the gun belonging to the Mother of the Family, and threatening to kill Baines. She then shouts at John to get everyone out before making a run for it herself when one of the Family's creepy scarecrow soldier turns up and snatches the gun from her. (One of the episode's funniest lines comes from Martha moments later, when she hurtles out of the village hall to find John and Joan standing outside still: "Don't just stand there, MOVE ! God you're rubbish as a human!")
The three of them get back to the school where John sets about sounding the alarm (ringing a handbell in this case) and telling the boys to arm themselves to fight against the Family. The Headmaster turns up and berates them without bothering to find out what's going on (pompous ass!), then agrees that the boys should be armed and, ignoring Martha's advice (since she's merely a servant), goes outside with another teacher to talk to Baines and the others (who've arrived by this point). The second teacher (a Red Shirt if ever there was one, since I can't recall his name !) is killed by Baines and the Head flees back into the school. The boys then set up a barricade in the courtyard, although Latimer runs off, still carrying the fob watch. He uses it to try to distract the Family once the Scarecrow soldiers have all been shot (though not killed, because you can't kill a scarecrow except, perhaps, by burning it).
John, Martha and Joan then flee the school and head for a cottage that belonged to the parents of the little girl (with the red balloon) whom the Family have taken over, and on the way there Martha insists that John has to return to being the Doctor because only he can save them from the Family. He gives a moving speech about wanting to remain John Smith:
"I am John Smith. That's all I want to be, John Smith, with his life and his job and his love. Why can't I be John Smith ? Isn't he a good man ? Why can't I stay ?"
Shortly after they arrive at the cottage, Tim Latimer turns up with the watch and explains that it's been "talking" to him (he can hear the voices from the Doctor's consciousness that are trapped inside it). He tells John that the watch wants him to become the Doctor again, but he doesn't know why he's been able to hear the voices. Whilst holding the watch John suddenly, briefly, lapses back into his Doctor persona to explain that Tim probably has a low-level telepathic ability that allows him to "hear" the memories stored in the watch. He looks in terror at Martha and asks if the Doctor always sounds like that and she says he does. John wants to know why Martha and Tim want him to return to being the Doctor and Tim Latimer tells him:
He's like fire and ice and rage. He's like the night and the storm and the heart of the sun. He's ancient and forever. He burns at the centre of Time and he can see the turn of the Universe. And he's wonderful.
A speech that I have to confess had me in tears. Finally Joan asks Tim and Martha to give her and John some time alone, and she allows him to talk himself into becoming the Doctor again, although not without them first sharing a brief vision of what John and Joan's life could be - marriage, children, dying of old age knowing his children and grandchildren are safe (and kudos to the make-up and prosthetics people for the fantastic ageing job they did on David for the sake of one brief scene).
Finally John goes to the Family's spaceship (they've been busy firing on the village whilst John, Martha, Joan and Tim have been talking at the cottage) and offers them the watch, which they accept, but it's a trick - John has already returned to being the Doctor (although he uses the equivalent of "olfactory ventriloquism" (don't ask !)) to disguise his Time Lord scent in order to fool them. He presses a host of buttons which set up a feedback loop in the fuel lines that blows up the ship, then he punishes the Family in various fairly cruel and harsh ways. He then heads back to the cottage to invite Joan to go with him and Martha, which she understandably refuses. He heads back to the TARDIS, where Martha's waiting for him, and Tim turns up to say goodbye. The Doctor gives him the watch, which is just a watch now, and then they say goodbye and disappear. We have a brief scene of Latimer and one of the other boys from the school during one of the many WW1 battles just avoiding being blown up by a shell, and then the episode closes with the Doctor and Martha attending an Armistice Day service which Tim, as an old man in a wheelchair, is also attending, still clutching the Doctor's watch.
is an intriguing book, that's mostly a look at peer pressure, but also considers friendship and responsibility. 
