Almost every species in the universe has an irrational fear of the dark.
"It's like the bees, yeah?" Donna says. They're wandering across a vast plain, the crushed grass under their feet wafting up smells of mint and honey. It's rather making the Doctor crave a cup of tea when they're back in the TARDIS, but for now he jams his hands in his pockets and watches Donna watching the sky. Stars are coming out, one by one. "Vanishing. Only no one knows what's happened to the bees, but at least with stars you've already got an explanation. Burning themselves out and just fading away." She glances sideways at the Doctor. "That's right, isn't it? About the stars. We haven't got it wrong? It's all supernovas and black holes and red dwarfs and that?"
"Yes indeed." The Doctor stops and squints up at the sky. Not so many stars. He'd guess background light pollution from the planet but they're the only technologically capable life for two thousand miles in every direction. "Learn all that from your granddad?"
"Yeah. Oh, he'd love this. I should remember to take pictures. Or," she falters, seeing the look the Doctor's giving her, "bad information, too advanced, say no more."
"We should find out where the bees are," the Doctor says. Dusk is settling in and still less than a hundred stars. A constellation of fear begins quietly flaring to life in the Doctor's mind. "The sooner the better."
The goal is to outsmart death. On Earth there are legends of alchemy and elixirs, life and gold unending. There are legends of some hidden spring offering up eternal youth. On Gallifrey the word for legend is the same as that for history. Time Lords keep meticulous records. There is no need for stories when scientific brilliance has already done the trick. Twelve regenerations, a full cycle of life, coded into Time Lord DNA; afterwards, the Matrix. No data is ever truly lost.
Legend/history, perfect equivalents. Fairytale in Gallifreyan is one small inflection from warning. On Earth there is a fairytale: once upon a time two men set out to face and defeat Death so that they might take his treasures, and were told they might find him upon a hill. One stopped in the town to find food, and met his comrade bearing a poisoned meal, so that the treasure would be his alone. The other, thinking the same, resolved to stab his friend after supping. So in greed both met death upon the hill.
No parallel story exists on Gallifrey.
(Once upon a time, a little boy ran away from the Capitol into the mountains because he was afraid of his eighth birthday. In the mountains he found solitude but no solace, and was nearly ready to turn back when he met a fellow traveler on the downward path. The little boy asked after the traveler's name. 'I am the Toclafane,' the traveler said, 'and in good faith, my name for yours.' Because the little boy was not yet eight years old he had only his true name to offer, and the Toclafane knew him. 'You are afraid,' the Toclafane said, and the little boy admitted he was. 'You do not have to be afraid of growing, nor of life and death,' the Toclafane said. 'I can take them from you. Should you like that?' The little boy thought about this, and agreed. So the Toclafane took the little boy's life and death, stripped him of his regenerations and ate his soul.
Behave now; say your catechisms and go when you're told, or the Toclafane might get you too.)
Not all skies are made of diamonds.
They're revising for exams. Technically.
Technically they have data pads and mathematical spreadsheets and books of formal poetry, but these academic trappings are cluttering up the available living space in an excitingly creative fashion. At this particular precise moment in time the diligent pupils Koschei and Theta are, respectively, working out the schematics for a customized latest-model TARDIS and writing a complex theorem for recreational maths in the fifth dimension, a type they are not due to cover for at least another four years.
"I don't understand why you won't just do the work," Koschei comments to the world at large, prodding the central console module with his stylus. "I've seen your marks. They're abysmal."
"Sneak," the other replies with little venom. "It's boring."
"You're just easily distracted."
Theta huffs in absent annoyance and finishes off a particularly difficult curve. Eighteen uninterrupted hours and he might have a viable solution to the paradox. All these endless circles. "Koschei, what did you see?"
"The transcripts. The Academy's Matrix records are depressingly easy to hack."
"No," Theta says, tearing his gaze from the proof. "I mean in the Schism."
Koschei's face goes blank. "The answer in return for your name."
"Ha ha." Theta sits up. "Quite frightening." Fiddles with his pencil for a moment, silly affectation that it is. "I saw life, you know. Over everything. Too much to quantify."
A long pause. "Me too," Koschei says, and goes back to his schematics.
In Gallifreyan, the lingual distinction between the words life and death depends entirely upon context.
For example: in the last great Time War, one living being in a single action obliterated the lives of billions so that billions more might live. The Time Lords never had a word equivalent to the Earth's utilitarianism. The Doctor doesn't either. Instead he has words like doing the right thing and running away, and depending on context sometimes they mean the same thing too.
The Doctor's not much good with misplaced things, but he is good with mysteries. "We've done Vespiforms already," he tells Donna cheerfully. "Insects a specialty!"
"As long as the bees don't turn up again eight feet long, hive and all," Donna retorts, prodding through a collapsed and apparently homeless skep hive. "Anyway, I don't understand. Can't we just go a bit into the future and ask around? They'll know what's happened."
"Not necessarily," the Doctor says, grinning over at her. "Where's your sense of adventure?"
"Again, only an adventure if the bees are eight feet long." Donna frowns, kneels to poke in the dirt. "That's some funny shapes. And why are you so interested?"
"Just like a good mystery, me." The Doctor crouches down next to her. "Funny shapes?"
The soil has worn away from an old concrete slab, and inscribed in the pavement are the complex fractals of High Gallifreyan. No -- the Doctor prods it with a gentle finger -- not inscribed, simply worn in, a message he alone in the universe can read. Death/life. The old theorem.
"Doctor?" Donna asks, and the Doctor says, "We're leaving. We're leaving now. I know what's happened."
A certain linguistic tense, now lost, describes things that used to always be, and now never are. Travel between dimensions. Paradoxes fixable without the unnecessary fuss of screaming and death and reality rending. A certain sort of databank immortality, thousands of souls with a unique print of Time Lord DNA ready to be called back to breathing life in a new body at the least thought. Then the Doctor burns it, and it's gone: the planet, two planets, two fleets of warships and all those casualties across the stars, and he ends it, but he ends the Matrix and god and heaven too.
When he regenerates in the new universe that has now always been, he is, for the only time, astonished by it.
They're proper studious scientists, drawing up lists of experiments and plans and conducting them thoroughly. Koschei has better handwriting.
To do: see this universe as it begins and as it ends (the old theorem). Grow and fashion a TARDIS and understand the inner workings of its heart. Understand regeneration; there is nothing they are too young to know. Quantify emotion.
"That one should be easy," Theta says, sucking absently on the eraser-end of his pencil. "That's just hormones at certain levels and specific connections in the neural pathways. It's probably already been done."
"I looked," Koschei answers, stepping up behind him, chest to Theta's back, hands over his hearts. "Not one thing." He leans in and breathes in Theta's ear, "They claim to know everything and they haven't even begun."
Hormones at certain levels and very specific connections in Theta's neural pathways cause his hearts to race and his mouth to say, with a shocking lack of eloquence, "I, er, Kos --" before it fails him when Koschei licks the junction of his neck and jaw in the spirit of scientific inquiry.
They research this thoroughly.
Quite a while before Theta is ready to check off quantify emotion and move on, Koschei apparently gets bored with the whole thing and jumps off the top of a tower. The appropriate portion of the Academy is properly scandalized, and Koschei is called before the Council to be reprimanded for reckless regeneration. Theta hears all of this secondhand, and again from Koschei himself. Koschei has ginger hair and pale eyes now, and looks altogether a bit more like Theta than he did before. "Maybe it means something," Theta suggests to this stranger, and the stranger becomes Koschei again by kissing him. This new version does it with less finesse, but with such focused attention that it turns Theta's knees weak.
Later he gasps "You feel different," and Koschei laughs. Theta isn't sure if he likes it.
The humans have a legend of Koschei the Immortal. Koschei, the legend says, keeps himself so by locking his soul away in a hidden place; he cannot be killed by mere bodily harm. Of course the humans complicate the story unnecessarily with all sorts of nonsense about the elaborate hiding of the soul within an egg within a duck within a rabbit within an iron chest buried under a tree.
The truth is far more simple than that.
"So what happened?" Donna demands back in the TARDIS. The Doctor swears and fiddles with dials and hits the console with a hammer and doesn't look at her. "Doctor, what happened?"
"Too many unknown variables," the Doctor says, and knows this is unhelpful. "Originally everything the Time Lords did was always there because they could keep it that way. Only now that they're gone they never were; all sorts of times are in flux now and disastrous things are happening." Donna stares at him. "It's like trying to stop a hundred leaks in the piping with one piece of cheesecloth, all right? It can't be done and the darkness is seeping through."
"Darkness," Donna repeats. "Like --?"
"Death," the Doctor says. "Void. I don't know. But the thing is, Donna, it's not the sort of problem where we defeat bad people and go off for a cup of tea. This is the sort of problem where we shift reality."
"Oh, good," says Donna, looking a little shell-shocked. "So far I've caught death, tea, and us somehow needing to do something to reality. What can I do?"
"Hold on tight and hope," the Doctor replies seriously. The existence of one Time Lord isn't enough to gum up the cracks, but two just might do it. The universe held up quite well under dramatic paradox with both of them there to bear witness. And he recognises the writing in the pavement, life/death, burned under his eyelids into his dreams.
The place and time: a field outside London, 2008, early morning before a smoldering phoenix pyre. The Doctor strides through wet grass, dew soaking through his trainers, and starts sifting through the ashes. Donna turns up behind him and sneezes. "Go on, then," the Doctor says, glancing up and allowing an apologetic grin, "if you want to help dig around in here and help me look for a shiny ring."
She finds it, which is probably a blessing; drops it in his hand and there it sits, a shining little ring with the Lazarus Labs logo stamped on it. He'd missed it at the time -- too busy blowing things up and running about in cathedrals, he supposes -- but there it is: life/death, immortality in a data chip, god in the details.
"Donna," he says, turning to her. "I'm so sorry. I have to take you home."
Her face wavers and sets. "Why?"
"I'm going to do something dangerous. Massively off the scales dangerous, not the fun kind. If it doesn't work out I'll be back for you in a second, I swear, but for this I need to know you're safe."
She looks as though she wants to do violence, but she agrees.
Alone in the TARDIS the Doctor hooks the Master's ring up to the console, lets the TARDIS scan and read and unpack all the relevant information, and there he is, memory saved at time of death minus injury. He sways and the Doctor catches him and he laughs dizzily against the Doctor's shirt. "Like Pavlov's fucking dog."
"Not exactly," the Doctor says. "If we're lucky you just prevented the end of the universe."
The Master laughs harder.
It is a little funny.
Tomorrow they will be opposites again, or experiments. Tomorrow there will be saving imprisonment history legend life death and perhaps a bit of tea.
Tonight they sit together in the grass and watch the stars come out like diamonds.