Author's Notes:
A nice long chapter to make up for the wait. Enjoy!
Summary: The Doctor returns to Gallifrey to learn how this all began.

The Doctor throws the door wide and is greeted with the unimpressed faces of Yaz, Ryan and Graham, all glaring at her.

“You went off without us,” Yaz accuses. “Again.”

“No.” The Doctor denies. “Well, yes. OK. I did, but I’m back now. Did you get everything? Trainers? Did you bring us pizza?”

“It’s cold by now,” Yaz says, evidently irritated. “You were supposed to meet us at 6, it’s almost 8.”

“Sorry. We had an urgent call.”

Yaz still doesn’t look mollified, but she does follow the others into the TARDIS, dropping the pizza box onto the step (where it is promptly forgotten), and joining the Doctor by the console.

“What was so urgent?”

“Oh...some people needed help. And we found out my timeline is disintegrating.” The Doctor keeps flipping switches.

“What?!” Ryan and Graham demand in unison.

“Nothing to worry about.” She turns another dial and dashes around the console to poke at something on the other side.

“To be honest, it sounds like it might be something to worry about, Doc.”

“OK, it might be something to worry about. But,” she continues brightly, “we’re going to stop it from happening.”

Yaz stares at her, but the Doctor doesn’t look up. “Are you going to tell us who’s disintegrating your timeline?”

“Uh. Me.” She throws the main lever with force.

Yaz sighs heavily, still hurt about being abandoned in Cardiff. “Right, ok. That makes loads of sense.”

The temporal column starts moving with a groan, and the Doctor turns back to Yaz. “Right. Recap. Basically, an early version of myself is being controlled by a vicious demigod from a different dimension and is being used to create chaos by being forced to act in a way that is against the principles of the Time Lords. She’s sowing discord in her own timestream with her actions, and bringing the wrath of Gallifrey down on herself. Eventually, she’ll be removed from time, taking out all the versions of me that come after her.”

“And how are we going to stop it?”

“No idea, but I’m sure something will occur to me. Eventually.”

“Where are we going then?”

“Gallifrey.”

The TARDIS stops moving.

“What? Really? But- isn’t Gallifrey...gone.”

The Doctor turns, staring at the doors. She’s as tense as Yaz has ever seen her, looks almost ready to snap. She doesn’t make eye contact with any of them.

“Barren. No life will ever grow again, but the planet itself, even the ruins...Intact.”

She’s perfectly still, Ryan notices. The Doctor never stands perfectly still.

“Doctor. Why here?” Yaz asks gently. “Why do this to yourself?”

“Because I need to know why I did this. I need to know the exact details of this bargain. I need to see my past.” She looks like she’s forcing herself to move as heads for the doors of her TARDIS. With anxiously swapped looks, the others follow.

It’s the first time in a while that Jack has truly missed his sight just for the sake of being able to see. To finally walk on the surface of Gallifrey and not be able to see what the Doctor had once described to him seems colossally unfair.

The Doctor has given him a new set of sonic sunglasses, but the green lines do nothing but stop him bumping into things, no consolation for being unable to see the red grass or silver trees he’d once heard described with such longing. It is eerily, unnaturally silent. He grabs at Yaz’s jacket, pulling her back a little to ask quietly, “What happened here?”

He senses more than sees Yaz dart a quick glance at the Doctor, but she is some way ahead of them now, leading quickly into what Jack assumes is the citadel.

“I’m not sure, she never says much.”

Jack nods. Always talking but never saying anything, he remembers the frustration well.

“When we were here last time, it was already ruined. I think the Master did it. And he was here, he had a plan, turning Time Lord corpses into cybermen.”

“Cybermen that can regenerate?!” Jack demands in horror.

“No. Yes, but there aren’t any. There was a weapon, powerful enough to destroy all life on the planet. And the Doctor used it. Killed the cybermen, and the Master, I thought. But she seems convinced he escaped.”

“Or maybe just wants him to.”

“Why would she want that?”

Jack smiles, and doesn’t try to explain. He knows he can never fully understand what the Doctor does, but he knows what it is to live long enough to see everyone you care about die of old age, to see whole planets move on without you. He knows every shade of the complex swirl of betrayal, of wondering if you could find the right code to reset everything back to how it had been, of wondering what you could have done differently, of knowing that you had been the one to hurt them first.

He hates the Master with a fire few humans could match. He’d suffered at his hands; had watched everything and everyone he cared about suffer at his hands, and the fact that most of them didn’t remember it and that it had been, relatively, several hundred years ago, had done nothing to quell Jack’s loathing. But he understands why the Doctor does not.

“How did the Doctor escape?”

“No idea.” Yaz shrugs moodily. “We thought she hadn’t for months, then she came back, but she never talks about it.”

Maybe she saved the Master too, Jack thinks but doesn’t say. That would be just like the Doctor, saving everyone she could before making a planet uninhabitable, cyberman collaborating psychopath or not.

“I thought Gallifrey was long gone,” he says instead.

Yaz looks at him.

“There was-” he’s not sure of the detail, he’s only heard the story in myth, and in that single unguarded moment when the Doctor had reminisced when they first fought the Master. “A war. A war for time. And Gallifrey- I thought it was gone then.”

“If there was a war...maybe that’s why she doesn’t talk about it, too many bad memories.”

“Maybe.” There’s a heavy silence between them. “Is it beautiful? He talked about it like it was beautiful.”

“It’s a burned out husk, Jack.” The Doctor interrupts harshly. They hadn’t realised she was near enough to hear, Jack always forgets she has much better senses than he does. Before he can apologise though she’s continuing in a voice both brusque and brittle, “No plant life, no animal, not even bacteria. We are the only living things walking on this surface and if we stay too long- No. It isn’t beautiful. Not anymore.”

Yaz gives him another quick look and then takes a couple of steps until she’s shoulder to shoulder with the Doctor. Without Time Lord hearing, Jack can’t hear what they are saying, but he sees the Yaz shape brush closer to the Doctor shape, sees the fingers entwine and looks away. His role with the Doctor has never been to offer tactile comfort.

They all stand in respectful silence for a moment. It is the Doctor that breaks it.

“Come on. We can’t be here long, but I need a quick look at the archives.”

They follow her into a building, and through labyrinthine corridors. The Doctor is never anything less than certain about her direction, always moving with purpose, but it is obvious to Jack from the speed and surety of her paces, that she has been here before. His brain itches with tension even though she has said there can be nothing here.

“Jack,” the Doctor says, and he follows the unspoken directive, moving up to her side. “I’m going to use the Matrix to get any information I can about her. Do you have anything that could give me a starting point?”

“Like what?”

“Well…I’ve met her, I could just do an image match, but it will be quicker if I can add keywords, filters if you like. Did she say anything that might help me pinpoint where her timeline intersects with mine?”

“Uh. She said she was the first of you, that she’d never regenerated.”

“Untrue. Anything else?”

“She always acted as though she were under orders. Someone had told her to achieve certain outcomes. She always said she had to keep the timeline pure.”

She doesn’t stop, doesn’t falter, and takes another corner sharply, “Pure?” she demands, word a whip crack. “That’s what she said? She didn’t say intact or safe, she said pure?”

“Definitely. I think I’d remember.” He tries to keep the edge out of his own voice.

“That sounds like a particular goal, a manipulation of time. Planets. Where did she take you? When?”

“She was at one of the labour rebellions on Taxxon 7, ensured the government was able to retake control, helped bring down the monarchy on Evianel, she was involved in selecting the diplomat that orchestrated first contact between Earth and Alpha Centuri too, but it wasn’t a name I know and I studied that. It’s a seminal bit of politics.”

“Those are all tipping points.”

He looks at her blankly.

“All moments when the universe could have gone off the rails and imploded or exploded, war and fire and conflict. No one ever making any progress.”

“So what does that mean?”

Her voice is grim. “It means that I’m being used to court disaster, and I don’t much like being used.” She pauses briefly as she enters the next room.

The sonic sunglasses pick out steps and a couple of doors leading into further hallways or antechambers, in the centre there is a curved dais.

“Don’t stand on the platform,” she orders without looking at them. “I have no idea if the Master’s paralysis field is still active.”

Ryan, who had been in the process of sitting on it, leaps up and gives it a wary look.

The Doctor stops by the entry to one of the rooms Jack had noticed. She doesn’t turn to look at them. “I won’t be long.”

“Doctor, wait!” It’s Yaz.

The Doctor does turn then, piercing green eyes focusing on her friend’s face, but her own expressionless.

“You don’t have to do this alone.”

“I do.”

“We wouldn’t- we don’t think less of you, Doc,” Graham promises awkwardly.

She sighs through her nose. “I’m going to use the Matrix. It’s a computer, Kind of. It’s a repository of all Time Lord knowledge and I’m going to interface with it telepathically. I’m not sure if human brains can do it and I am certain it will damage you if you try. Just wait here.”

“We should still go with you,” Yaz insists. “Psychic communication is dangerous, you’ve told us that loads of times.”

“I haven’t. You’ve been watching too much telly.”

“So it’s perfectly safe then?” Ryan questions.

“‘Course it is. I’m always careful. Careful is my middle name.”

It is only because of the gravity and sadness in the Doctor’s eyes that none of them laugh. She sighs again. “Okay, well. I’ll be careful this time.”

Yaz is still looking at her.

“Fine. Yaz. But don’t touch anything. And the rest of you stay here.”

Yaz gives the others a quick smile. “I’ll look after her.”

“Shout if you need us,” says Jack.

She nods once and spins back to follow the Doctor’s receding shape.

The Doctor leads Yaz down a hallway with a steep incline and into a room so vast it seems to be a covered open space. It feels as though they are underground, some sort of cave system perhaps. Usually, Yaz would ask, but she senses that right now the Doctor isn’t up to explaining.

Their footsteps ring in tandem across the stone floor. It’s the kind of place that seems like it should echo, but doesn’t, heavy air instead swallowing the sound.

“We just need an access terminal,” the Doctor says, half to herself. “The Matrix is telepathic, it can access any Time Lord mind from anywhere, although closer the better, but I want to query it, want to be able to use its index, not just get probed by it.”

“So you need a terminal?”

“Probably. I haven’t...well. I have broken into, and out of, the Matrix before. But I haven’t exactly done this.”

“Like every other day then,” Yaz says with a quick smile.

The Doctor smiles back, her eyes lighting briefly. “You don’t have to be down here, you know. I know it’s creepy.”

Yaz shakes back her hair. “I’m coming.”

The Doctor doesn’t argue further and gives her a brief, but real, smile, before leading them across to a carving on the floor. It’s a swirly figure 8 kind of symbol.

“I’ve seen this before,” says Yaz.

The Doctor paces the edges of it. “Yeah,” she agrees absently. “It’s everywhere here. It’s the sigil of the Pyrdonian Chapter.”

“What does that mean?”

“It’s a...faction. School house, I suppose. The government system of Gallifrey is split into Chapters which are groups, or parties, and it goes all the way back to where you are placed at the academy. You’re placed based partly on lineage, but partly on skills and attributes.” She bends brushing over the carving carefully.

“But this mark is everywhere, there’s one in the room we came from.”

“That’s a council chamber, where important things are decided. The Pyrdonian Chapter is the ruling elite. Rassilon himself is supposed to have been one. The one in the council chamber, in the centre of the dais, is a terminal too. But I didn’t want to use that again, in case the Master left anything else unexpected in it.”

Yaz wonders if that’s true or if the Doctor just wanted privacy to discover what her past self had done. She feels briefly guilty for forcing the Doctor to accept her intrusion. It’s incredibly rare for the Doctor to open up like this though, so her guilt doesn’t stop her from asking, “Which Chapter were you part of, Doctor?”

The Doctor is now touching other random parts of the carving and it is lighting up in a sequence unintelligible to Yaz, but that obviously means something to the Doctor as she squats next to it. “Hmmm? Oh. Pyrdonian. The Master and I both were.”

Her voice is vague, attention mostly on whatever the lights are telling her, but there’s a hint of pride in the words too, old and worn but still there. The Doctor looks up, and the moment is broken as her mouth quirks in a mischievous grin. “I used to be High Lord President,” she says lightly. Then, before Yaz can ask any follow up questions to that surprising announcement, carries on, “I’m going to make contact now. I’m not sure what it’s going to look like from your side, but I don’t recommend trying to disconnect me from it. That could have consequences. Messy, brains squirting out of my ears, consequences.”

“How will I know you’re okay?” Yaz asks. That’s what she’s supposed to be here for, after all. “When we found you lying on top of the one in the other room last time, you looked half dead.”

Something softens in the Doctor’s face and Yaz aches. It’s like the Doctor, for all the good she does, doesn’t realise how deeply she is loved in return. She offers Yaz her arm, and then, on reflection, takes her screwdriver out of her pocket and offers that too. “You can take my pulse, if you want. Same place as yours, remember it’s a double beat. That’s normal. And take this. If anything does go wrong, this’ll take you back to the TARDIS, put it in the charging slot on the console and it’ll take you home.”

Yaz settles her fingers on the Doctor’s wrist, feeling the steady thrum of life beneath deceptively delicate skin. “We won’t need it.”

“No. Of course not. This is going to be absolutely fine. Take it anyway.”

Yaz does so.

The Doctor gives her a slightly nervous smile and slaps her hand down flat in the centre of the carving. The whole thing lights up, a glow so bright it’s almost painful, Yaz slams her eyes shut and clamps down tighter on the Doctor’s arm. She’s bathed in the light being burned by it, incinerated by it. It’s looking at her she knows with soul deep certainty, judging her.

The light keeps shining, blazing, if possible, ever more brightly, but Yaz feels the sudden sensation of something between her and it, something a cool blue that shelters her from the glare and she knows, without a shadow of a doubt, that it is the Doctor’s mind. She still can’t open her eyes, the blinding light still literally present, but she can breathe again, feels less oppressed by a weight that had felt unnatural and searing. Her fingers tick back to the pulse points the Doctor had guided her to. They’ve picked up slightly, but not, she thinks, dangerously.

She cracks her eyes open for a second, the Doctor is face down and lax and the flaming light seems somehow to be bending over her. It’s enough to pick Yaz’s heart rate up, but before she can wonder if something has gone terribly wrong, the light starts to writhe and move, it changes colour and, as it recedes in brightness a little and Yaz can open her eyes more fully, she picks out not just colours but figures, and realises it is projecting an image.

She leans a little closer. A cell, she thinks at first, not too different from ones on Earth, ones that she has spent any amount of hours doing training in and on. There’s a woman, sitting on the edge of the bed along one wall. A Time Lord, Yaz can tell that just from her outlandish dress sense. Like someone who’d tried to make a gothic Mary Poppins costume.

For a second, she thinks it’s the Doctor. Not this Doctor, obviously, her face is different, but why would the Matrix be showing some random Time Lord?

Then another figure comes into view at the cell door, a smaller man in an equally ridiculous outfit with a haircut that Yaz associates with old pictures of John Lenon. He’s wearing the same kind of cloak the Master had dressed his cybermasters in, goldy-orange and shimmering.

Yaz leans closer as words begin to come from the image.