10: Plokhoy Volk

Trying to decide between crushing apprehension and arrogant, ecstatic bliss is one of the more strange choices he's had to make in his life. Over the next technically unpassing hour, he does not land definitively on either option.

He spends the better part of that time curled around Rose, tasting the twitch of her heartbeat hiding under the fine linen paper of her skin, dropping kisses to accompany a freckle on her sternum and the round of her shoulder. It's only half that time before he's lured in again by the sweep and press of sweat damp skin; by her low, still-anxious laughter. The chilled tip of his nose slides along the upturning bridge of hers to find lips already parted for a long, slow kiss that feels like falling, like time and space dissolve around them, like he is once again made only of energy and not a framework of flesh. It's a heady feeling, like a materialized dreamworld he never wants to leave.

Before he's even cognizant of what he's doing, he's palms down on the table above her, neck bent with her legs coaxed around him a second time with more confidence than before, chasing away the anxiety that's trickled through from a reality whose well being he cannot and will not be indentured to any longer.

Instead he seeks that foreign sensation of existence as a still life painting, where everything stops except for them, the sliding, the deep push-pull, the tangled limbs and sweat. He'd think of a clever title for it all, this erotic impressionist canvas in his mind-something artistic and abstract and very physical-if his brain was at all running at any percentage of its typical capacity instead of inundated with dopamine and oxytocin.

When that muscle-seizing moment arrives again, he pictures a mythological concept of a flat Earth, the sharp edge of existence ending abruptly and the whole of an endless ocean pouring over the side and into dark infinity. A painting that could be called The End of the World-but on second thought, hardly a still life.

He wilts in an imagined pink haze, eyes closed, blood evaporating along the tracks of his veins, burning up like lines of gunpowder. In the quiet between labored breaths, she giggles, hands on his back and a smile he can hear flashing unseen over his shoulder. "Whatever happened to not being able to wait even twenty minutes for stitches?"

He feels himself laugh, hears it even, but he's almost disembodied by pleasure and exhaustion, existing in a state of higher consciousness but intoxicated by the slow damp petting of her hands on his naked back; the rise and fall of her expanding lungs, everything physical about her that's naked and golden and grinning. This is a glimpse of the Rose that's been waiting under the soldier's posture and unflinching command, the shoulder bent under a weapon and eyes grown depthless and stark.

"You are persuasive," he tells her. "And I have become immensely distracted."

"I remember when you groused at me because I just assumed you didn't." She draws the word 'assumed' out, there is a smile in her voice that he loves hearing and loves thinking about and loves seeing when the flash of her white teeth cut through the shadow enough that he can discern her mouth. He drops to his elbows and kisses it.

"I was talking about dancing."

There's that smile again, her head inclining far to the side. "No you weren't."

"Rose Tyler. That was a long time ago. I can't possibly be certain what I meant. But. To be fair, you did just assume that I didn't."

"I still assumed that after. At least the dancing bit."

"Well," he demurs, carefully pivoting on an elbow to settle to one side of her. "As you recall, I simply stated that I could. Conditional. Not that I generally, you know. Do. Or...did."

The conversation is about to deteriorate strangely, he can feel it in the air. His head swims a second while she blinks, biting her lip with her eyes cast low under her eyelashes. "If you didn't...or don't...then why..."

"Why?"

"Why didn't you? And why now? Why..." she clears her throat and swallows just tightly enough he can hear every centimeter of her flexing throat. "Why me?"

His voice jumps so high it nearly cracks. "Why you?"

"I just...I don't want you to do things that are unnatural for you just to make me happy..."

"Did I give you the impression of powering through a chore?"

"No!" Now she laughs, high in her throat. "Just..."

"Rose, you don't want to hear the entire gruesome detail of biological imperatives toward procreation for species whose life-expectancy spans centuries, appropriately limited-release gonadotropin and resulting societal stigmas based on lower caste behaviors."

"Doesn't sound much like pillow talk, I'll give you that."

"In any case, nothing that makes you happy could possibly be unnatural. And it's not so much unnatural. Just...unprecedented. Cross-species. Though," his shoulders jump with a sudden anxious-sounding chuckle, "I guess not as much as I'm inclined to believe. Worth noting that interspecific...or rather I should say intergeneric cross lifeforms are almost universally sterile. It's a biological expedient, preventing gene transference."

Rose erupts into loud laughter. Her head drops back onto the bright blue vinyl padding, shoulders bouncing and from his angle, all he can see is the delicate triangle of flesh under her jaw, the long column of her throat taut with delicate cords of tendons and velvet skin.

"I'd rather," she wheezes, "I'd rather you not phrase it as though you're a horse and I'm a donkey."

"Not what I intended," he corrects primly and she only dissolves into spasming, soundless hysterics. "Besides. I'd sort of be more of a mule."

Rose laughs harder, rolling to her side and burying her face, the sound flattened by the interference of the vinyl and her folded arms. She comes up on her elbows, breathless, face lost in a blonde tumbleweed. "Alright, then, fine, you're a mule, you romantic git, but that's not what I meant and you know it. Wait-this hasn't...happened to you before, has it?"

The Doctor is quiet a moment in the ringing afterglow of her merriment, like the silence after a peal of bells. Resting his head on one folded up arm, peering over at her in the light that shifts like fireshadows. "You mean the metacrisis?"

Rose's breath puffs with the threat of more laughter, she twists her mouth to tamp down the impulse to laugh at the idea that she might mean anything else. "Well, I had meant the metacrisis-"

"I have to admit, it's my first." He reaches for her, hands on skin in a new and thrilling way he knows he will never be entirely accustomed to, no matter how long he may have to try. And after a quiet moment of embrace, Rose has lost the impulse toward levity.

"I mean it, Doctor. Why me?"

"Rose-"

"No, really. I'm not stupid. For a long time, I thought I was. Most of my life, even. It wasn't until I met you..." She shakes her head. "I'm not even as idealistic as you might think I am. I know you've been around so much longer...I can't even begin to imagine what it'd be like, living that long. You've been places, seen things I can't comprehend. You know details of...I dunno, moon colonies and historic battles and things that I don't even know exist and I just...I wonder why you'd want to spend any time with me at all, much less..."

When she trails off, there is just the sound of rain, the robotic moan of wind breaking up against sharp-edged architecture.

"Rose..." he begins, and his brain is buzzing with chemicals, fight or flight, the amygdala lighting up like a holiday display, and he can only excuse his failings. "I am total rubbish at a few things. Just a few, mind, but...that kind of...that's one thing I just...I don't know where to begin. I don't know what to say that doesn't come out sounding all wrong. There's any amount of science behind why anybody does anything that explains virtually nothing at all when it comes to motivations. Emotional responses ingrained over time. Despite logic and justifications, there's always an element that remains almost inexplicable. Why does anybody do anything? Why do we love what we love? Why are we so drawn to things, to certain people?" The Doctor clears his throat and shifts. "Maybe it's because we can't help it, it's just the nature of thinking things-to love something recklessly, to want to be close to it even if it's supposedly wrong or-I don't know-of if it can only end in misery."

"So instead you walk away without saying goodbye?" There's an edge in her words, something that cuts, and this is not where he'd wanted this to go at all. "It's still goodbye even if you don't say it."

"I'm sorry I don't have a better answer. It's a difficult question, I don't know if I can explain."

She makes a methodical, wet sound. Like she's licking her lips or opening her mouth to speak long before words actually come out. "Bit rich, you not being able to explain something. So...that's all, the nature of things and all that?"

"It was like...finding a key to a locked door," he says, eyes to the skylights now, feeling small and strange and once more gripped by the perpetually unnerving feeling that he is in over his head. "I wasn't looking for it. Maybe I didn't even realize the door was locked. You are...the exception to everything I've ever known about myself. You are an answer to a question I didn't know, like something written in another language I couldn't read and it was both maddening and spectacular and I wanted..." His voice falters, the volume of it dropped so low it's nearly inaudible. He breaks off with a huff of frustrated breath. "I'm not saying what I mean to say at all."

It's Rose's hands on his face now, her voice thick in a way that reminds him of a holographic image of her windswept face, saying goodbye when she was already so far away. It feels like a thorn lodging in his lungs to hear it. "Yes, you are," she says. "What did you want?"

He swallows with some difficulty. "Being with you made me feel...good. Maybe that sounds simple to you. But honestly, really good. And...I hadn't felt good in...oh, Rose. Such a long, long time. And then, just like that, you were gone. And so was the feeling."

There's silence now, Rose winding herself around him again, the damp sound of her open-mouthed breathing.

"Are you crying?"

"No," she lies, then sniffs loudly.

"I'm sorry," he says, and he is. She's not crying for him. Not this version of him. Because no matter what, it will always be there, stretching long behind them like shadows just before sunset, like the echoing ache of an old wound: the idea that he'll never be entirely what she'd wanted.

"Stop apologizing."

It's a long time after before either of them speaks again. They've both settled into each other as though this isn't the most remarkable thing, their laying together nude on a padded exam table, exhausted and sweat damp with slow breath and closed eyes.

"Don't fall asleep."

Nodding heavily, he tucks his cheek against her neck-though miracle of miracles, he almost could. He's got one foot in a dream already, standing balanced on a high cliff overlooking the end of the world with an ocean pouring off at a hundred-million gallons per second. Donna is there, on an outcropping far below, standing face to the wind in a sodden wedding dress. Craning her neck back, hands balled in tight fists at her side, she opens her mouth and yells up at him.

"Doctor! You can stop now!"

He starts; blinks back the rising exhaustion, finding tears stinging in his eyes for reasons he doesn't have the energy to question, and it's another twenty minutes and one more painkiller before they make it out of the medical wing in Torchwood training wear salvaged from the laundry, walking slowly with fingers basket woven together and a damp warmth collecting between their palms.

Still, he hasn't decided between anxiety and arrogance yet, and walking up the ramp to the cannon module, he abandons both choices.

He freezes completely, another moment of still life and this one would be titled Shock. Not just because the dimension cannon is a lot smaller than the preposterous contraption he'd envisioned by its name alone, but mostly because he's seen it before.

Or at least, he's seen something like it before. Something that gives off the same electromagnetic signature. Remarkably like it. But certainly not any more alike than it feels. Certainly not.

He's moving forward like a fish on a hook, towed forward by his nauseated curiosity and grabbing the heavy binder from the console's shelf. It's a terrible epiphany that's an hour late; one that should have come when his mind was empty and time was standing still but is only now pushing its way through through the backlog of thoughts.

He opens the binder in the center, page forty-six of the program manual detailing the hardware breakdown, when the initial anxiety blossoms into dread. Because every explosion has an epicenter, and they have just found it.

No. None of this was an accident. There is no such thing as an accident.

What he's looking for in those binders isn't a thing she asks because he'll answer. He'll answer and she'll be no closer to knowing than where she was at the start, so instead she watches him, folded up ridiculously in the tiny glass-enclosed module control with the open binder in one hand, one long leg with the word TORCHWOOD trailing down the toward his bare ankle. Squinting from the black and white circuitry schematic to the open control board with his brows dropped low, his eyes snap side to side while he pages through in what looks far too fast to be reading. The lines of his face grow more taut by the second, the long shadows of his eyelashes stretch down his cheeks, spider leg long from the overhead lamp. He looks surreal this way, lit up against the dark wall of machinery and readouts; he looks like something she would have dreamed up to crawl into her bed at half past midnight.

"The cooling unit implies maintenance of a critical temperature," he says absently, enough that it's unclear whether he's addressing her or just thinking out loud. "Restrictor plates keep a sub-zero temperature in the coil chamber. Default setting point-zero-three Kelvin, it's no wonder it needs a whole river working on a heat exchanger..." He exhales a low whistle, then face-faults almost comically into expressionlessness. It's several beats of silence before he continues in a strange, strangled sounding voice Rose isn't certain she's ever heard from him before. It's sepulchral. Hollow. It inspires a disembodied dread that starts in her throat and sinks lower. "It's running a niobium chip."

"And that's...bad, is it?"

His mouth moves but no words issue. It hangs on whatever unspoken thing has robbed him of every syllable he might use to communicate. Like the thought is too big to fit through the meager opening of his mouth.

The world might end after all: the Doctor is speechless. Expressionless. His face-she's seen it lit up in anger and sorrow, features twisted into sneers and laughter and only recently contorted in breathless passion. Now he's just blinking at the manual contents, only half in English, his mouth hanging just open enough for breath to wheeze out from between his lips. He reaches into his pocket and withdraws one of the yellow receiver pads, turning it over in his palm silently before setting it on the console frame.

"Doctor."

He clears his throat. "This isn't. This shouldn't...exist."

"It's an alternate world, Doctor. I told you, loads of things are different here."

"No. No, that's not what I mean." He shakes his head in slow motion, his voice coming out brittle and dry, like leaves breaking up in the wind. "It's not just a little off, Rose. I mean, it's off. Practically a thousand years, and considering Moore's law, that's saying something. This is displaced technology, it has to be. Tetranuclear niobium oxo-acetate chipsets aren't even synthesised until 2817 in Old Earth chronology. And here this is, running a niobium chipset cooled to just off absolute zero-Torchwood built a quantum mnemonic engine and it's just..sitting here in this cellar..."

He stops, snaps his mouth shut almost audibly, his mind changing directions so abruptly she can almost hear tires squeal. In the sallow light, his eyes come up from the binder text to settle on her, and when he speaks, it's in that half-strangled way. "You let them put you through this thing."

And she means to, but she doesn't answer right away. Watching the expressions roll across his face is like watching storm clouds in time-lapse photography. It can't settle on any one thing. It's worse than when it had chosen none at all. "It's fine, Doctor. It's safe."

"Safe!" he snaps, so loud and abrupt she actually starts from the sudden gunshot sound of it, reverberating back in the little glass-enclosed booth. Immediately a hand scrubs over his face and through his hair, while he shakes his head with a kind of mirthless gust of laughter coming out with his breath.

"Doctor, you're scaring me."

"This machine, Rose. This machine can perform 2^512 calculations simultaneously. That's more atoms than there are in the entire universe, and then some. It generates probability variance at Planck scale using material cooled below critical temperature to negate the electromagnetic force and create a Meissner effect. It expels all electromagnetic fields while the inside of the reactor reaches a superconductive state, below the rate of particle resonance. Sound like anything you've heard before?"

She's ready to shake her head, except, inexplicably, it does. It rings a rusted bell in the back of her head, because it does sound like something she's heard. Just where she's heard it-that's the part she can't remember.

"The reality bomb. Torchwood's Dimension Cannon is the essentially the same type of machine with a different power source. Instead of single-string zed neutrinos, this thing pulls a couple million joules per second, you were right about that part. But safe...no. There is nothing about this that's even remotely safe."

With a breath, Rose shakes her head, blonde dandelion fluff fallen in her eyes that she swats away. "Waitwaitwait, hang on-"

"It stands to reason this isn't a coincidence. Us, trapped here, existing in a shorted out time differential. The existence of something like this, this is the catalyst for all of it."

"But...Davros... he wanted to destroy everything."

"Technology is neutral to concepts of morality. Even the most well-intentioned discovery can and will be used for destruction eventually. And the other way around. You can use nitroglycerin as high explosives or to treat heart conditions. Same difference."

"I don't understand. How could it be the same?"

"It's not the same, just essentially. The same way, oh, I dunno...a toaster is the same as a nuclear reactor." He gestures with the hand that isn't holding the binder, floating in the air before landing on his head like a nervous bird. "Same idea, different applications. Both generate heat. Different fuel source, same result on different scales. Negate the electromagnetic force, matter just falls apart. Nothing to hold it in its shape. This machine uses the same kind of effect, but it uses its superconductive state to expose point-particle probability and manifest multiple states in macroscopic density. Multiple realities. At Planck scale, gravity breaks down. Probability field quantifiers at near sub-Kelvin temperatures slow particle resonance enough to expose multiple simultaneous states. In essence, this machine peels apart m-branes and-for the soul brave enough to walk in there-lets them walk right through to whichever specific state the operator solidifies. Like walking through a two-way mirror." He shakes his head, flipping a page with an almost hostile jerk. "It's a great trick: exchanging particles with half-integral spin like electrons for particles with full-integral spin. Like photons. Gravitons."

Rose's throat has run dry. So much of what he's said means nothing to her; it's just the way he's said it all with an increasing tone toward anger. Half-leaned inside the little glass booth, she watches him intently paging through the end of the binder, reading schematics that look more like pages of computer errors and strings of random numbers than they do any kind of parseable information. Nearly four years she's been at this, she's buried her head in books and slept an hour a night and seen the sunrise from a hundred different versions of reality and in ten minutes he's made her feel so wildly out of her depth as though they've never been apart. It's a comfort almost as much as it's utterly maddening.

"They told me it measured timelines," she says. It feels like an inadequate addition to the conversation, but little of what he's said has made any sense beyond the clear and obvious indication that the machine is not only dangerous but something bordering what he feels is impossible.

But impossible is just a word, and as a concept has rarely been more than a hindrance, in Rose's experience. She's stepped over cracks in the ground more ominous than the word impossible. And for the last four years until this morning when she'd woken to find everything tipped on its ear, Rose Tyler-the new new Rose Tyler-ate impossible for breakfast.

"It could be said to," he says heavily. Every word is a stone falling out of his mouth. "Certainly. A proficient operator could scroll through probability to find optimum states to solidify and send the coordinates to the receiver. The receiver discs, they're probability field quantifiers with radiation shielding, dematerializing matter via electromagnetic harness and reconstituting it to calculated supersymmetrical specifications based on highly specified coordinates..."

The Doctor stops talking but does nothing. Doesn't raise his eyebrows, doesn't gesture. He sits without words or motion for long minutes that pass like seasons before continuing in a flat tone that sounds like reciting something long memorized. "It's a quantum apparatus. A nibioum-acetate powered superconductive device; this close to organic. It can parse block transfer computations without adapting to their logic as law. Who built this?"

Rose wants to reach out, but for whatever reason, doesn't. "I'll introduce you to the team, Doctor. God-they're going to love you."

"This machine could devour us. Devour everything. The fact that it hasn't already..."

He's staring at the binder pages, eyes glassy. There are words on the page: bosons and superfluidity and angular velocity but he does nothing, doesn't elaborate or even look up. His hair has fallen over his forehead and he leaves it.

"This machine is our only way back, you said."

"I said that before."

"Doctor. You'd rather-"

"If a malfunction of this machine, or-hell-just the ongoing use of this machine weakened the hold on wave functions...like..." He puts out a hand, palm up, fingers flexed around something invisible while he thinks up a metaphor. "Like stretching out something elastic so far it can't pull back into its original shape. Our coming here could trigger that. Us with all our mass a whole second out of sync with the rest of this reality's dodgy particle decay rate, setting off a chain reaction." Passing both hands over his face, he shrinks in the module seat, shoulders rounding. "A machine that uses quantum entanglement to unravel timelines one at a time, like pulling a thread in a jumper-it's going to weaken timespace around it. And if we don't use it-"

With an visibly angry flourish, the Doctor powers on the monitor in front of him. The power-up interface loading before the program initializes with a quick splash screen with the program name in Russian letters that look like a tangle of barbed wire, then the familiar plotter screen showing a digital clock-arm swinging in awkward orbits, leaving plotted trails in various colors that weave together in peculiar parabolic arcs with a long string of numerical readouts, statuses, temperatures. Rose has never been certain as to how it works or why, but she knows what it's displaying. Watching it, he makes a sound that's sharp and dismal.

"It's a funny old life, isn't it? The things that come back around when they do," he pauses, then wheezes out a bleak, unhappy laugh. "Looking at this interface is like if I showed you what colors sound like."

"Not sure I follow." What a surprise.

He shakes his head. "A visual representation of temporal chaos theory, it's just...odd. To look at something that's...usually something in your head. The Lorenz plotter model for values leaves a lot to be desired."

Rose covers her face with both hands. "Sometimes," she says, with her voice muffled into her palms, "I wonder why I even bother asking."

"Time is deterministic. Look at this pendulum, see how it's bent here, hinged to modify its center of mass. Motion of a complex multi-dimensional metronome maps out generalized co-ordinates of gravity and inertia in a dynamic system. Initial conditions are strong influences of resulting differentials."

He points to the screen along the colored trails left by the end of the swinging double-pendulum on a black background. "Think of this point being, I don't know, the moment you walked into the post office, or a coffee shop where you ran into someone you hadn't seen in ten years. While you're talking, she mentions a position that's just opened up at a company she's just left." He moves his finger to a different colored loop. "And here is where you interview for and are offered that job that your old friend recommended to you." He moves his fingertip further still. "And here is where you meet the managing vendor that works with a branch of your new company."

One more move to a blue loop along the outside of the increasing rat's nest, and when he speaks again it's dolefully; so profoundly sad. "And here is where you get married to him. You'd have never gotten to this loop," and he moves his finger back to the first position, "if it weren't for this one. But we can't take every opportunity to exist in a linear state. Free will is an illusion of the organic mind. Reality is just a consensus, what we've all agreed is real. Just like we agree for currency to have value, or that laws are to be obeyed." With a punch of a keyboard function, he cycles through the different colored loops. "There is no reality. All these loops already exist, different variations, and just for now you can see them out the skylights. You see them in your peripheral even here, pushing against the fabric. Original values-starting points-have everything to do with resulting secondaries. Infinitesimally small changes in original conditions can yield an enormous difference in long term results. Like the difference of one minute on a cosmic scale, or five seconds. A quarter of a second can be the difference between life and death. A trillionth of a second in quantum time. This is why the weatherman's usually wrong. This is why not even a Time Lord can look into these spirals of possibilities and see any one defined result to anything. Only this. What just looks like chaos."

He gestures to the screen, and his voice is dark and heavy, like a storm cloud ready to break. "This is a physical representation of an iteration function system to recreate a natural structure using inertia, kinetic energy and potential energy as stopgap values to represent aspects of eleven-dimensional spacetime but..." He nods, eyebrows low and eyes severe as though any of that explained anything at all; as though he really expects her to understand any of this. But even she knows, understanding isn't the point of the Doctor letting his mouth run away without him. He could well have come up with a less magnanimous story, one of car wrecks or derailing trains because you stayed too long at a traffic light or spent one more minute in bed.

"This is a timeline plotter. This is how they found Donna." With another movement of his long fingers, he points out a single point just above the pendulum where all the colored lines come together on their way back or away. "Where all the timelines converged. And right now, that's us. Eye of the storm, more or less."

"More or less?"

"Well. Maybe less rather than more," he says. "But maybe it just starts that way."

Rose feels like throwing up. All at once she wants to ask what else he can see, could see, could ever see about her, about them, about this moment right now. But most of all, she wants to ask if the other Doctor on the beach knew that this would happen. Or if he was too much of a coward to look at those spiraling colored loops in his stupid selfish thick Time Lord head-

But in her own head, there's poor Donna saddled in a heavy coat, covered in wires and straps. Surrounded by mirrors, she dissolves into shuddering half-swallowed tears while she stares down the nightmare that's clutched to her back. "Turn it off," she begs. "Please."

Rose has studied chaos theory as it applies to her travels-initial points, cause and effect, the butterfly effect of correlating points and the causal nexus. She understands, but she doesn't. And maybe she's had enough of seeing other realities, everything that could be, everything that is-all that potential for suffering held in that swinging pendulum. She couldn't stand it in her head, never able to turn it off. And maybe it's unfair to think he'd want to see it either. That he'd even want to look at what he'd decided he couldn't have.

"You can graph any dynamic system. Rise and fall of water levels in a river network," he says, eyes focused on the screen while he cycles through input fields. "Wax and wane of animal populations. Disease epidemics. Graph any deterministic system and patterns emerge. You find recurrence plots, cycle limits and strange-attractors. Everything's a number. Graph any system and the results approach..." and here, inexplicably, he laughs, like it's suddenly clear there's no point in explaining. Or trying to explain. "Someone spent a long, long time designing this machine to determine those cross points in possibilities and to open them up and deposit someone into that coordinate of time. It's...the most dangerous thing I might have ever seen in my life and you've been just launching back and forth like it's nothing."

"Enough already. I had to do something. You should know I didn't build this bleeding thing, but having a kind of purpose-I don't know what I would've done otherwise. They'd been designing it a long time before I got here, but it gave me, I dunno. Hope? Something to focus on; something worthwhile. It was something that actually felt familiar, I could immerse myself in it and I just felt... And then the things we observed. Timeline activity dropping with no observable cause. Bloody stars vanishing, whole galaxies. One by one, more every day, I suppose you'd just ask me to stay put because it's too dangerous and expect someone else to help, yeah? Who? There isn't a Doctor in this universe!"

She's no faster said it than his shoulders have drawn up tight, everything about him gone tense and wooden. A muscle at the junction of his jaw twitches, and his eyes fall back on the dimensional receiver disk sitting on the edge of the console.

"Doctor...I didn't mean it that way."

"I guess you said it best, Rose. There's no Doctor here, you might as well take the title. Good job of it too: leather jacket, a blatant and intentional disregard for your own safety."

"Don't talk like that."

"I'll talk how I like, thanks," he deflects, and there's a bittersweet familiarity to his words. He hasn't sounded so much like that old self in ages. All that's missing is a Northern accent. Perhaps he would say the same of her.

("This is who I am. Right here, right now, alright? All that counts is here and now, and this is me!")

Maybe she's always been in doubt of who he is, from the start, from the very beginning. He is both caprice personified and world-defining unto himself, the question and the answer: a dichotomy that is nothing new. Not ten minutes before they were nude, locked together in the intimacy of breath and sweat, broken voices and shared humanity, and now once more, she barely knows him at all.

Swallowing conflicting impulses to strike or embrace him, she breathes in slowly through her nose, then out her mouth. It's a relaxation technique, learned in therapy between rounds of attempted treatments she's refused because he'd called it companioning; it makes her think of memorized terms like "complicated bereavement" and "pathologic grief". Back during those blurry months where she could only tell time by the appointments: one week equalling another trip to see Gary in his suit and leather chair. That was before Pete had brought her in on the D-Cannon project. Before she'd had a reason to get out of bed at all.

With a grim face, he keeps entering data, strings of numbers, more of that incomprehensible library of values and variables filed away in his brain.

"Doctor. Please."

"Those disks, Rose, the field quantifiers. You don't use them for the initial jump through the engine, do you?"

He's not going to address it, that's clear. He's not even looking at her. "Only once you're out of range, yeah."

She watches him blink, his eyes on the screen but not looking at it. "Yeah," is all he says at first. It takes him another minute, surveying that swinging pendulum and its pixelated rainbow loops, flipping back through schematics in the open binder and back to the readout before his presses his lips together, puffs out his cheeks and sinks into the stiff-backed task chair in a kind of deflating slow-motion. The Doctor breathes in, then out. He has his own way of dealing with grief. It's a moment before he reaches for her, gathering her against him in the tiny booth, leaning into her embrace and every touch of her hand with the intensity of a neglected cat.

"And when you send more than one person," he continues quietly, speaking close to her ear. "You do one at a time, twenty minute cool down between each. You can jump simultaneously once they're through. Right? Out of range?"

Rose nods. "The initial power-draw isn't enough to safely process more than one person's mass and link it to their receiver, I'm sure there's a better explanation in there if you care to look it up, afraid I'm not quite an expert-"

And she trails off. The Doctor is staring at the floor, the smallest shiver of liminality visible even in the polished concrete, like a two light sources shifting back and forth intermittently; like a fluorescent light with a bad ballast.

Neither of them have to say it aloud. She knows. They have to go through one at a time.

It's a conglomeration of misfortunes, a collection of results moment by moment, but not an accident.

The damaged cooling system, the observer effect, the liminal prison that swallowed Jackie Tyler. Probably going much further back, those wider reaching arcs of probability, the existence of worlds and civilizations, constants and variables that span millennia.

Time is deterministic. One second can change everything, and this is their reality even though neither has conceded to it. Rose surprises him by tugging back, she meets his gaze with placid eyes, the color of honey and he wants to fall into them. Wants to close his eyes and fall, like dropping off that plummeting edge of the world as he'd once imagined, everything fading to black and they could both wake up somewhere oceans away where it's already tomorrow. Where all of this is over. Where it never happened at all.

This machine is temptation given shape. The kind of temptation that devours principle and time. Devours finality and causality, rewiring reality, a display of everything that is, that was, that ever could be.

Oh. And somehow, he should have known. With the manual still in his lap, the Doctor pages numbly back to the manual title page. It's the same cyrillic characters he'd seen flash by so quickly on the power-on splash screen that he'd simply passed them by, the name of the plotter program: плохой волк. Plokhoy volk.

Bad Wolf.

It's correlation versus causation. Here at the heart of things; what came first, the program or the entity, Rose Tyler or the Dimension Cannon, the chicken or the egg, the locked door or the key-all of it here, inextricably linking them with every fiber of the warp and weft of the temporal vortex. It's so easy to forget that he doesn't turn the cogs of time.

Forever and ever, they are turning him; every him.

And he could rewrite everything, every second since that tent in Shan-Shen or even before; he'll unmake himself entirely before he'll leave Rose behind again. Here where there is only the two of them in the whole world. Where there are no Time Lords, no laws of time except in his head.

She's been speaking, but he hasn't heard. He's still staring down at the manual title page, his head clamoring too loudly to let anything through the grind of his thoughts. To get his attention, still halfway leaned into the open module booth, Rose reaches up to the glass beside her face and she knocks. Four times.