Archive of Our Own ^beta

Chapter Text

The Doctor shoves their way through the snow and into the TARDIS. They stumble inside and push the door shut with as much force as they can manage, which isn’t much. The inside of their skin itches like a paradox, their headache is so intense they can barely think, and their cirri are slipping off the timelines one after another. But they can’t let go yet, they can’t be seen -

They make it halfway to the console before they collapse.

The world goes dark. Sight, sound, telepathic contact, their senses have been failing for years but never so completely. There’s - something’s wrapped around them, all of them, thin but tight, binding them so much they can barely breathe. Their thoughts still fuzzy, they instinctively flare their talons and rip -

The sterile white light of their TARDIS’ control room washes over them, bright enough to dazzle the photoreceptors on their finials, and they think, oh.

It takes a few minutes and a significant amount of tearing, but they manage to drag themself out of their old moult. They bite onto the console, hook a scythe into its wiring, and pull until the last segment of their primary tail clatters onto the tile. Their emptied-out husk slumps, temporospatial manipulator limbs falling out of the higher dimensions and collapsing in a lump on the floor, tridimensional manipulator limb folding in half over the hole in its torso.

They stare back at it for a moment. They’re not entirely sure what to do with the thing.

Slowly, groggily, they examine their new body. It’s larger than their old one - that was barely long enough to stretch over one of the console’s panels, this new one can easily wind around all of them with room to spare. They rotate their lateen fins, flick their spines, clack their talons and their carapace against the instruments and each other. One of their mouths (they have three of those now!) randomly lolls open, and the atmosphere’s flavour is so unexpectedly sharp they nearly fall off the console. They can taste the elements in the air again! They missed being able to do that!

The ringing in their mind is slowly clearing up, and they decide to try something. Tentatively, carefully, they spread their wings (there’s a new set near the base of their tails, that’ll be handy) and climb off the console and into the air. Their old body would have creaked and jolted with every jerk and twist, but this new one flows through spacetime with a careless ease. They perform a complicated four-dimensional pirouette, marvelling at its smoothness.

The bottom portion of their lateral wings are still imprinted with the patterns of their old set, pockmarks and streaks of colour and all the impressions of a body well used. Past the edge of their old wings, their filaments are pure shimmering silver, ready to be painted with their new life. They whistle through their spiracles. Maybe -

“Doctor!” a voice yells. Something bangs on their TARDIS’ shell.

For a moment, they can’t tell what’s making the sounds - where did that noise come from? For another, they can’t figure out what’s making them - is something leaning against the shell? Then they recognise the sharper sounds as speech, and an instant of pure panic shoots through them - something’s trying to get into my TARDIS - before they peek out into the timelines, and realise. It’s their human friends, Ben and Polly! They unthinkingly reach for the siphon toggle on the mental console, but before they flick it, they pause.

Ben and Polly. Their human friends.

It’s been a long time since they were truly afraid of their human travelling companions, but they’re still wary of calling attention to some things. Their tridimensional manipulator limb can pass for human with a little bit of effort, and that little bit of effort lets them pass unnoticed through so many of the back-alleys of the universe. They’ve found it easier to just not bring up the fact that they exist in many more dimensions than their companions, and that their form in those higher dimensions isn’t the most humanoid. Human reactions to the completely alien are so unpredictable, after all. Best not to risk it.

Except now their old tridimensional limb is sprawled on the floor, shredded and twisted in ways that aren’t entirely three-dimensional and very obviously attached to the heap of carapace and filaments sprawling behind it. They’re still a bit too dizzy to properly examine the way the potential timelines spiral out after Ben and Polly see it, but they know enough about humans by now to make an educated guess.

But. “We’ll freeze to death out here! Open the door!” shouts Ben or Polly or both (their timelines are similar enough it’s a little difficult to tell them apart right now.) And Ben-and/or-Polly is right, if they don’t open the siphon their friends’ timelines either peter out entirely or slowly drift away from them. They won’t let their friends die, they decided, and they definitely don’t want to travel alone.

Yet what can they do?! The mess of shattered armour and spattered fluids on the floor is utterly outside of human experience, what possible explanation could get them out of this?! They try to flip their new tridimensional limb open so they can at least talk to Ben and Polly, but the additional sensory feedback is too overwhelming, they snap it back shut before their headache can get any worse. Every second the TARDIS stays locked their friends’ potential futures dwindle a little more, they need to let them in, but they can’t let them see -

The banging is getting frantic. They skitter back to their moult, casting desperately around for anything that might vaguely resemble a plan. With the faint idea of throwing the thing into the TARDIS’ xylem, they try to get a hold of it, but their delicate, fiddly hooks and spindles are too frail to go hauling big three-dimensional objects around, all they manage to do is rip open even more gouges and snap off a couple of sheaths. They could maybe drag their main body in their mouths, but its tridimensional limb is more than twice its size and a lot bulkier on top of that. Half the limb’s tendons are torn off already, they really don’t fancy trying to force it shut again, especially not with that gaping hole in its torso -

Their frantic scuttling stops. A few secondary eyes and an artroreceptor battery spiral open to take in the whole scene. They stare at their scattered less-than-humanoid parts, and at, at the same time, the hole.

A plan begins to coalesce in their mind.

3.78 minutes later, the TARDIS’ doors finally open. Ben and Polly almost tumble inside, but with the warmth the TARDIS gives off the cold has done them no permanent damage. Ben pulls the doors shut behind him with a firm slam, and Polly shivers all over, rubbing her hands together. A few dimensions above human perception, the renegade Time Lord who hasn’t decided if they’re still calling themself the Doctor waits for their friends to spot their moult.

They’re quite proud of their work. It took a fair bit of creative thinking and some hasty surgery to carve out a cavity in their moult large enough to stuff their nonhumanoid parts inside, but now all their transdimensional limbs and segments are safely hidden from human eyes. They plugged up the hole as best as they could manage with their more shredded articles of clothing and covered it all with their cape, carefully and artfully draped to conceal all the remaining gashes and bends. The TARDIS cleaned up all the remaining internal fluids and random bits of carapace, and now there is no indication that the body on the floor is anything more than human.

The TARDIS’ main siphon irises shut, cutting off the roaring winds outside instantly. In the low background hum on the console room, Polly looks up and glances around. “Doctor, where -“

She spots the corpse on the floor.

“Doctor!” she shrieks, and the Time Lord watching from above realises they may have made a mistake.

Chapter Text

The night the Time Lord who was not yet the Doctor fled Gallifrey, they were cut off from the Gallifreyan hive mind for the first time in their life. They were skittering around the dilapidated controls of their stolen TARDIS when an immense and terrible pain suddenly ripped into their mind, tearing at its edges until a last blinding wrench left them clinging for dear life onto the console while blood dripped out of their carapace.

The pain faded soon enough, but the quiet that crept in to replace it was so much worse. Their entire existence had been set against the backdrop of the hive mind, they had spent every moment of every day immersed in a sea of thoughts and speech and memories, always supported, never alone. But now that endless conversation was a distant echo in the back of their mind, faint and growing fainter. Even with their psychic antennae fully flared out, the only other sophonts they could hope to brush against were the acolyte soundlessly shuddering against the wall and the alien hum of the ship itself. Outside, the Vortex stretched on forever, silent and empty.

Out of all the awful things that happened that night, that creeping unshakable realisation that they were completely alone in the universe was one of the worst.

They got used to the loneliness as the years went on, though it never really went away. Step by excruciating step, they taught themself to function outside of the hive. They learned to rely on no one else, so that Arkytior could at least rely on them, and they tolerated this aimless solitary existence, because it was an existence nonetheless. They took what joy they could find in it, a task that grew steadily easier as time passed before ceasing to be a task at all when they began travelling with humans and found the kind of sincere companionship they’d for so long thought impossible. But even after their last-gasp desperate flight turned into their wildest childhood dreams come true, that hollow sense of isolation never completely disappeared. Time after time, the kludges and inaccuracies of spoken language would get in the way of them making themself understood, or they’d find themself juggling twice as many timelines as they had hooks while running for their life in the third dimension, or come across a wonder of the universe that existed in dimensions their companions couldn’t even imagine, and, despite everything, they would wish they were among their own people again.

As the Doctor peeks onto their homeworld for the first time in over a century and the all-encompassing presence of the Time Lords engulfs their entire being, they wonder how they could possibly have pined after the endless cold disdain of the hive.

The second the Doctor leaves the bounds of their ship the Gallifreyan hive mind blasts across all of their senses, flooding their universe with controlled cacophony and casually and inescapably pulling them back inside. Its intricate weave envelops the whole planet, its lengthy threads stretch out across reality, and its endless unpicking and respindling whirls on all around this insignificant timeship dock dangling off the Citadel’s judicial web. Messages flit back and forth through the collective mindscape, memories rise out of and fall into the great pool of the Matrix, and clusters of minds synchronise to hash out consensus and make decisions. Low-castes bustle through distant radials, timelines rattle and thrum as they’re carefully tended, and beneath it all, the Vortex hums.

It should be familiar. It is familiar. Gallifrey is exactly as it was when the Doctor last lived here, from the low squabbling on the edges of the hive mind to the silvery taste of chronons in the air. They remember fitting into this grand tapestry so seamlessly they couldn’t imagine existence outside of it, partaking of and adding to the never-ending cascade of observations and analysis and choices. A full battery of psychoreceptors they’ve never used in this instar automatically unfurls, antennae fan out to receive and project the constant flow of information they were designed to transmit. Slotting back into the hive should feel like finally coming home.

Only it doesn’t. Their antennae and psychoreceptors and everything else slip out of alignment, and though they consciously force them into the correct form it’s a strain to hold them in a position that should be automatic. Data pours into their mind from the rest of the network, but rather than routing through the expected analytical and confirmatory channels it goes spiralling off on bizarre unpredictable pathways, coming out barely recognisable and mostly useless. The black hole of the Matrix tugs at the Doctor’s memories, but they hesitate to give them up, to let their secrets fall out of their spindles and into the assembled knowledge of the Time Lords. Everything that should be as easy and natural as the winds of Time is awkward and difficult and alien, and they can’t figure out why -

In a single ripple of awareness, the hive mind notices the misshapen node in its vast workings. A thousand million gazes focus on the anomaly, examining and evaluating their clumsily bent antennae and their hopelessly tangled mind. The Doctor’s very self is weighed and judged, and a swift consensus comes: they are unfit, far too deformed and ungainly to serve the deep hive mind’s processing needs. As impulses slowly reroute around them and their people’s collective consciousness grumbles at the inconvenience of it all, the Doctor’s sputtered protests rapidly trail off.

The hive is exactly as it has always been, so the only element that can have changed is themself. Their journey has changed them so much from what a Time Lord should be that they can no longer function as one, and they don’t know how, or even if, they can fix themself. They wished so many times that they could just go back home, be cared for and supported and safe, but in the midst of the bustle of Gallifrey they are as alone as they ever were in the emptiness of the Vortex.

The isolation is as cold and as harrowing as it has ever been. Somehow, they know they will never belong here again.

“Doctor?” A warm hand lands on their tridimensional limb.

It’s Jamie. His hand rests on their shoulder, as rough and weather-beaten as the texture of his mind brushing against their antennae. “Are ye all right?” he asks, and loud concern ripples through his wariness and confusion. Zoe’s deep enough into the TARDIS the Doctor can’t reach out to directly read her emotions, but they catch alarm flitting across her consciousness as she bustles in their direction. All their companions have seen is their tridimensional limb suddenly freezing still just outside the TARDIS’ primary siphon lip, they realise. It’s no wonder they’re starting to fret.

“No need to worry about me, Jamie, I’m fine,” they say automatically, raising one of their hands to rest on his and winding a spindle into his timelines. They’re far too rattled to sift through the possibilities for something that will actually reassure him, but instead of challenging them Jamie grips their shoulder tighter and glances around the dock with renewed suspicion. Roiling protectiveness thrums through his mindscape, and the Doctor leans into that respite from the disdainful gaze of the hive.

Zoe is harder to dissuade. “Really, Doctor,” she says as she marches out of the TARDIS, “if this is your home planet…” She comes to a pause as she takes in their surroundings. Unlike Jamie, Zoe is very familiar with how humans and humanoids design their spaceports. The Doctor isn’t sure how much she can perceive, but this vibrating woven honeycomb of timeships arranged without particular concern for gravity or the Euclidean laws of geometry is far more inhuman than anything they’ve let their friends see. A tiny spark of that old fear darts across their mind before they can quash it.

Zoe inhales, quiet and sharp. Then she reaches out to grasp the Doctor’s free hand.

Alone in the heart of the Citadel, cut off from their people’s hive mind and facing down the might of the Time Lords, the Doctor is nevertheless surrounded by warmth. Their companions’ bodies radiate heat, their minds rage with faith and resolve, their potential futures intertwine with the Doctor’s in a weave so tight they couldn’t unpick it if they tried. Now as they have so many times before, the three of them form a united front against the terrors of the universe, and though the humans are as unnerved and exhausted as the Doctor is that only makes their friends pull them in closer. Even now, their minds hold no doubt or fear of the Doctor. Their friendship and trust and solidarity are far too instinctive for that.

Scientifically, the Doctor knows why their human friends are staying by their side. They know about troop dynamics, reciprocal obligation, hyperactive agency detection, all the little evolutionary quirks of humanity’s fluid, expandable social networks that, given the right context and incentive, make them so much more able and willing to accommodate the strange than the hive ever would be. The strength of their loyalty still makes their antennae shake, and the depth of their love is still almost overwhelming. The assessments and requirements and judgements that defined life in the hive never so much as occurred to the Doctor’s human friends. Almost unconsciously, their many companions all held out their hands, and once the Doctor took them, there was never any question of letting go.

The beauty of it is enough to make their carapace rattle. How could they have missed the endless serrated labyrinth of the hive, when they had this?

In the warm embrace of their companions’ love, some of the tension seeps out of the Doctor’s mind. “Thank you,” they say, pulling their humanoid face into a smile and showing it to Jamie and Zoe in turn. For all its limitations and vagueness, there’s an art to physical communication they have quite a lot of fun playing around with.

“Nae bother,” says Jamie, squeezing their shoulder with an answering grin. His eyes flick around the dock once more, spotting - oh dear, that must be the Tribunal. “So, fit’s the plan?” he whispers as the three Time Lords glide over to them, blatantly unsettled by how their tridimensional limbs skate across the dock’s membrane in a movement that could never be mistaken for human. Against their polished carapaces and their immaculate wings, the Doctor just feels tatty.

Thorough disapproval and more than a little disgust emanates from the approaching Time Lords as they examine the Doctor’s party. But the hive mind has already cast them out, so the Doctor doesn’t see a particular need to care about their opinion. “Follow my lead,” they murmur to their companions, “stay close to me, and whatever you do, don’t draw attention to yourselves.” It’s rather unlike their usual approach to potential foes, but the less important the Time Lords think their companions are, the less likely the Tribunal will pay them enough heed to separate them.

All three of them brace themselves for the battle to come. Jamie takes his hand off the Doctor’s shoulder and shifts into a flexible fighting stance, Zoe narrows her eyes and drums her fingers on the side of her leg, and the Doctor lets their body slip back into its natural, guarded posture. As their psychoreceptor-covered fins fold back under their carapace and their antennae roll up into their usual rods, the constant chattering of the hive mind muffles into the indistinct roar they’re accustomed to after so long on the run. Their psychic ganglions twinge with pain, but it’s nothing compared to last time, and if they’re going to escape from Gallifrey again they’ll need every edge they can get.

Surrounded by their friends, their TARDIS virring encouragement at the edge of their mind, the Doctor faces down the Tribunal. They’re exhausted from days spent matching wits against the War Lord, but they can’t afford to slip up yet. It’s been a long time, but they still remember how to play Gallifrey’s game of hidden motives and hidden knives, and though they were never a master, they learned from the best.

It’ll take everything the Doctor ever learned, every tiny fragment of skill they gained both on their homeworld and out in the universe, to get themself and their people off Gallifrey intact. For Jamie’s curiosity, for Zoe’s laughter, for the warmth of their camaraderie and their hands, for the endless journey across the stars they’re only now realising they never want to give up, maybe, maybe it will be enough.

(It isn’t.)

Chapter Text

“Doctor?” Something taps on the TARDIS’ shell.

The tapping is light, regular, insistent. Coiled in the branches of the TARDIS’ upper phloem, the Doctor blearily wonders which sense they need to muffle.

The tapping stops after 4.5 seconds, but the voice continues, calm and professional. “How are you feeling? There’s been a break-in at the Ministry of Defence and plans for a secret weapon have been stolen. Your assistance would greatly benefit UNIT’s investigation.”

The Doctor’s only just figured out the voice is communicating with words when it falls silent again. They uncurl their body a little bit, enough to open a couple of sensory batteries and rest an antenna against the TARDIS’ siphon. There’s a small nexus of timelines and emotional vibrations in front of the doors that’s probably what the voice is coming from. It sounds familiar in a way the Doctor’s still too groggy to place.

“I can hear you moving around in there, Doctor,” the voice declares, its calm audibly beginning to fray. Beneath that enforced composure lies a mind taut with tension, suspicion and irritation and stress. It feels impatient. It feels demanding.

Well, the Doctor has better things to do than fold down their antennae and get lectured. They twist out of the phloem and arc down to the console, where they sequester themself above the primary rotor and start dialling in the disconnection sequence. The TARDIS grizzes disapprovingly at them, but once she realises they’re not going to stop she flens and her intakes start swelling with time. Even with their mind still fuzzy from the regeneration, the process of taking off has become so familiar the Doctor barely has to think about it, and soon enough the familiar grinding of the TARDIS unwinding her roots from inner reality echoes through their still-hardening carapace -

“No! No, Doctor, wait!” A voice from outside - a different voice, from a different mind. It’s rougher than the first, younger, far more panicked than irritated and far less thorough in disguising it. The Doctor can’t quite place where they’ve heard it before, but it definitely sounds familiar, they just can’t figure out how -

The second mind’s headlong dash towards the TARDIS’ doors comes to an abrupt, jerking stop. “Miss Smith,” the first voice announces, “please -” and all the Doctor’s skittering scythes and hooks suddenly freeze.

Miss Smith? Sarah Jane Smith! Sarah Jane Smith, their friend, who sneaks into places where she doesn’t belong and takes things she’s not supposed to have and never lets anything stop her, no matter what anyone says! Is that her? Is she here? She - wants them to wait? Why? Does she want to come too?

Without a second thought, the Doctor yanks the detachment process to a stop. Kirriking at them in amusement, the TARDIS starts weaving herself back onto spacetime, and the Doctor takes the opportunity to unfold their new tridimensional limb. This long after their moulting, the shock of its senses coming online is more of a brief jolt than an overwhelming blast. They flex and wiggle their brand-new joints, blink until their vision comes into focus, settle their heartsbeat into a regular rhythm. Just as the TARDIS’ shell is fully solidifying, they remember to wrap one of their old uniform’s long coats around their tridimensional limb. No sense in causing unnecessary fuss, after all.

A flick of the primary siphon toggle, and the placid, sealed spacetime inside the TARDIS melds with the ever-changing maelstrom of the timestream outside. Their tridimensional limb is still a little too wobbly to stand up by itself, so they lean on one of the TARDIS’ doors and carefully push the other open. Outside is - Sarah! “Hello, Sarah!”

Sarah stares. “Doctor?” The title is tentative and uncertain, which seems completely inexplicable until they remember she doesn’t know that they can moult. Confusion and tiredness and a tiny hint of fear radiate from her mind, consistent with her rumpled, unfashionable outfit and hoarse voice. What can have happened to put her in such a state? This won’t do at all.

Before the Doctor can remember enough English to comfort her, the body behind the first voice clears its throat. “May we presume you are, in fact, the Doctor?” inquires an officious-looking fellow in a trim and tidy uniform. The Doctor scowls at him, partially because they somehow get the impression he’s about to tell them off and partially because he’s still subtly angling his body between them and their companion. Who in the universe does this human think he is?

Wait. Isn’t that a UNIT uniform? Their real body is still slipping out of the TARDIS, but they have enough cirri on the timelines by now to recognise the UNIT base, less by its precise spatiotemporal location than by the familiar texture of the myriad tiny edits they’ve made to the local timestream. A UNIT uniform, on the UNIT base, a voice that expects to be obeyed, unflappable composure covering up even the greatest distress, a thin cluster of dark hairs above the lip… “Brigadier?”

The Brigadier’s left eyebrow rises a precise height. “So I have been informed,” he replies.

“Sarah Jane… And the Brigadier…” A note of wariness they’d barely even noticed dissolves away now that the Doctor knows they’re among friends. Said friends are still all worn-down nerves and held-back distress, but whatever’s made them so upset won’t be anything they can’t handle together. “Well now, isn’t this nice?” They smile, easily and instinctively. This face feels made for it. “I’m the Doctor, pleasure to meet you both again. What’s happened? No, wait -” Before either human can answer, they wind back through their conversation. “There’s been a break-in? A stolen secret weapon?” Oh, that sounds fun.

Their friends don’t feel nearly as excited as they are at the prospect of solving this mystery, which is expected in the Brigadier but downright baffling in Sarah. Beneath his impassive act the Brigadier doesn’t even feel relieved, while Sarah’s weary shock is being overtaken by a hot, bubbling anger. “Among other things,” the Brigadier states dryly. “Would you care to explain -”

“You can’t just act like nothing’s happened!” Sarah suddenly shouts. “You disappeared for three weeks and when you came back you died! Then your body exploded, the whole sick bay was covered in blood and other fluids we can’t even idenitfy, there were these long segmented tendrils flailing all around and shards of what looks like chitin scattered everywhere, because something forced itself out of the Doctor’s body and -”

She cuts off with a gulp, glaring at them through tear-filled eyes. The Doctor stares back. The last thing they clearly remember is collapsing on the floor of the lab, but a smattering of sensations that must be from after that are rising to the front of their consciousness. Scrambling desperately through a tangle of time towards a soothing, gentle song, the sharp pain of fresh plating denting, glass shattering around them…

For the first time since they opened the door, the Doctor properly examines their surroundings. Almost all of the furniture has been cleared out of their lab, and the few bits of shelving that remain are covered with splashes of orange and silver. The air reeks of twentieth-century cleaning chemicals that almost but not quite cover up the acidic reek of their own apolytial fluid. The overhead strip lights are off, probably because of the ominous crack straight across the casing of the one nearest the door. The window into the hallway outside is conspicuously lacking in glass, and something that looks suspiciously like a snapped-off talon sheath is prominently extruding from the opposite wall

“It seems to have fused with the brickwork,” the Brigadier comments idly, following their gaze. “Tell me, have you always been a transdimensional monstrosity from beyond the furthest dreams of mankind, or is this a recent development?”

The Doctor grins at him bemusedly. “I’m from Gallifrey.”

Extracting the sheath from the wall proves a somewhat more involved task than it probably would be if the Doctor’s new carapace had fully set into shape yet. It’s somehow managed to merge with the brick on an atomic level, and the Doctor has to carefully wiggle it out molecule by molecule until it tumbles back into its native dimensions. They come across many such small higher-dimensional accidents in and around the base’s corridors, scratched-up timelines and little tears in the fabric of reality and bits of shrapnel embedded in places they never could have reached following an entirely tridimensional path. The Doctor takes the time to fix them as they wander through UNIT HQ, testing out their new hooks and spindles and getting their new body used to the headwinds of outer spacetime. They’ve been doing this kind of idle timestream maintenance ever since they left Gallifrey, and the familiarity of it is obscurely comforting.

Although that may be because absolutely nothing else about this situation is anything they’re used to.

The Brigadier seems to be trying to steer them back to the sickbay, but the Doctor can’t summon the energy to kick up a fuss about it. Their tridimensional limb leans on him occasionally as they stagger through the halls, unfolding their sensory batteries and spreading out their wings. His emotions have settled into a more-exhausted-than-usual variant of his usual annoyance at their antics that cloaks a careful sort of suspicion. They know he’s only performing his duty as UNIT’s senior officer around an unknown factor, but it still stings.

Sarah follows behind them, glaring in their general direction. They think they’ve convinced her they are in fact the Doctor, more through the Brigadier’s vouchsafing than anything they themself have actually said, but that confirmation seems to have only made her angrier. Her footsteps stomp across the tile flooring, her hot gaze falls on everything but the Doctor, and she keeps a short but noticeable distance between her and them. Whenever they try talking to her, she pointedly ignores them.

The Doctor has wondered, sometimes, how their human friends would react to learning about their true nature. They have enough faith in their companions these days they trusted them to not run away screaming or dive for the weaponry, but even with that possibility off the table there was a whole spectrum of potential responses between casual, unthinking acceptance and automatic, terrified rejection. They’ve hoped for the best, and feared the worst, and eventually came to the conclusion that it was better not to take the risk. They’d found a comfortable status quo at UNIT and decided not to chance upturning the whole thing for no real reason.

They’re wondering now if that was the right choice. Perhaps they should have taken the opportunity to explain all this while their body and mind were in good working order, able to ease their friends into the concept before events had the chance to spiral out of their control. But even now, they’re not sure what they should say. What questions would a human think to ask? What would they want to hear to be reassured?

The tense silence stretching around the three of them somehow doesn’t strike them as the most ideal situation to find out. It certainly could have gone worse, but it could definitely have gone a lot better.

About halfway to the sickbay, while the Doctor is teasing a heavily cracked mug out of the temporal knot that has it turning mildly non-Euclidean aileron rolls in mid-air, Sarah finally condescends to speak to them. “What I still don’t understand,” she declares acidly, “is why K’anpo Rimpoche’s regeneration looked absolutely nothing like this.” Is that how the hermit translated moulting? What an awfully poetic way of phrasing it.  “He just faded away into Cho-Je in a matter of seconds, without any fuss at all. There was none of this…” The Doctor finally yanks the knot loose, and the mug immediately shatters. The Brigadier takes a hasty step back, and Sarah watches the whole display with tangible disapproval. “Mess.”

“Oh, didn’t you notice?” The Doctor shakes the nearby timelines a little, and all the falling ceramic shards scatter harmlessly over the floor. “Both of their bodies were projections. I’m not sure where their real body was hiding, it certainly wasn’t…” A faint shudder runs through the timestream, coming from out on the grounds. It’s far too strong to be an aftershock of anything they’ve been doing since they came out of the TARDIS, more like someone deliberately making a mess of the timelines while the Doctor isn’t around to stop them. They dash for the nearest window, half-expecting to find the Master cackling about whatever his mad plan for the stolen superweapon is. Instead they see half a dozen UNIT soldiers in the outdoor loading bay clustered around what looks like -

“Is that my moult?” they sputter, too surprised to think of a less alien translation for it. Then again, that ship’s very much sunk, hasn’t it?

“It was making a bit of a mess in the sickbay,” the Brigadier states, coming up to stand beside them. “Impeding the medical staff’s work and such, and it doesn’t appear to be particularly sanitary either. We – Doctor?”

The Doctor doesn’t hear whatever he says after that, because they decide that staggering all the way to the nearest exit and then across half the grounds would be far more difficult and time-consuming than simply pulling their tridimensional limb through the higher dimensions and depositing it outside. They hurl their limb around the wall with one big heave, and then they immediately collapse onto the tarmac, because most ancient memory of the vampires they are never ever doing that again. Their senses burn with the afterimage of time, their tendons ache from the strain of dragging a big heavy three-dimensional object into places it was never meant to go, and there’s a massive hole in the timestream the exact shape of their limb. This was a terrible idea, ow, ow.

It takes a full 12.42 seconds for the shrieking in their skull to die down enough they can process the physical world again. They scoot backwards until they hit the wall, lever themself back onto their feet, and stumble towards the group of soldiers, navigating more by timelines than by sight. Said timelines are noticeably ragged, lots of random tears and awkward-looking twists. “Hello!” they call out, making sure to smile. “What are you fellows getting up to?”

A small jolt of surprise runs through the fellows in question, but they immediately go back to their work. That work, the Doctor sees as their vision clears, consists of loading their moult into a flatbed trailer, a task made somewhat difficult both by their moult being just a little too big to easily fit in the bed and by segments of it occasionally tumbling in and out of tridimensional space. As they watch, the hollow husk of a hook casually drifts along the fifth and eighth dimensions, balances for a moment, and then drops back into the humans’ perceptive range a full metre clear of the trailer. One of the soldiers sighs and goes to pick it up.

The sound of a clearing throat draws the Doctor’s attention to a vaguely familiar UNIT man with a couple of stripes on his shoulders trying and failing to loom at them. “Sir,” he says in a passable imitation of the Brigadier’s most unimpressed tone of voice, “I’m afraid I’m going to have to ask you to -”

The soldier carrying the hook husk pulls it just the wrong way, and it skids out of his hands and into his timelines. The Doctor catches it before it can dig into his past, but there are several gashes there already, some of which look concerningly deep, along with some nasty-looking cuts. A quick scan of the other soldiers reveals them to all be in a similar condition, and though nothing seems particularly serious yet a couple of them have long-scarred-over nubs where they definitely had fingers this morning. “Do be careful with these, won’t you? They’re still quite sharp!”

A couple of the soldiers’ minds pique confused, and a couple more pique wary. Their apparent supervisor’s hand falls to his sidearm. “Sir, this is a restricted area -”

“DOCTOR!” Sarah bellows as she pounds across the tarmac, mind roiling with rage and an equally scorching alarm. “What did you do?!” She plants her feet about a metre away from them and folds her arms, glowering.

The soldiers pause in their work to shoot surprised glances at both of them. The supervisor stiffens into a ready stance. The Doctor tries a new kind of smile, this one a little softer. “Sarah! Nothing to worry about, I just thought I’d have a chat with these gentlemen about my moult -”

“Don’t you dare,” she hisses, looking about ready to slap them. “We both saw you faint! What was so urgent you couldn’t be bothered to use the door?!”

They’re starting to wonder that themself, but they’re not going to say that, obviously. “Well, it’s my moult, isn’t it? So I ought to be able to do what I like with it, shouldn’t I?”

“That’s not -”

“What Miss Smith means to say, Doctor,” interrupts the Brigadier, striding towards them with all the officious dignity he can muster, “is that someone in your condition ought not to go about doing…” He briefly flicks his eyes towards the spot where they collapsed. “Whatever it is you did.”

He doesn’t know it, but his gaze passes directly between the Doctor-shaped hole in the timestream. Sarah breathes heavily, fists balled at her sides. They don’t have the energy to try to justify their lapse in judgement, so instead they wave a hand slightly more erratically than they intended and say, “Let’s not fuss over details.” Sarah’s anger flares, but before she can start shouting again, they get to the point of the matter. “But really, what are you doing with my moult?”

Sarah growls and snaps her head away from them, but they weren’t talking to her. They addressed the question half to the Brigadier and half to the gaggle of soldiers, who have abandoned all pretence of trying to load the trailer and are now openly gawking at their little tableau. The supervisor glances at the Brigadier, receives a nod, and turns to face the Doctor, falling into parade rest. “Doctor! We apologise for questioning your clearance! We are preparing your moult for transport and disposal!”

“Disposal?” This question they address directly to the Brigadier.

“Incineration or somesuch,” he explains dryly. “Assuming we could find a furnace large enough it wouldn’t warp through the walls and into the machinery. Why, are you planning to do something with it?”

They haven’t really decided yet, but that’s not why they asked. It’s a relief to hear that they won’t have to navigate a tedious conversation with the Time Lords in the immediate future, but more than that, there’s something heartening about learning that even now, the Brigadier is letting them keep their secrets. “Well, it is mine. And…” Yes, it’d be much easier to fix the soldiers’ timelines when their moult isn’t in the way. “You’re having a fair bit of trouble with it, I can tell. Shall I take care of it?”

The Brigadier briefly boggles. “Can you?”

“Of course,” the Doctor replies, moving their tridimensional limb out of the way as their true body leans into tridimensional space. They bend down just far enough to pick up their moult, tails wrapping around its thorax, talons untangling its flailing limbs from the trailer’s wheels, hooks scooping its larger broken-off pieces off the ground. It takes them 44 seconds to carefully carry their moult back into its native dimensions, during which time they pay absolutely no attention to the humans. Gasps, pounding boots, and rapid cursing fill the air, including a particularly nasty one the Brigadier barely manages to cut off.

Once they have their moult safely stowed beneath a secondary set of wings, the Doctor leisurely takes stock of the situation around their tridimensional limb. The humans have all scampered away from the trailer, clear of the tiny shards of carapace scattered across the tarmac. The soldiers are huddled together a good ten metres away from the Doctor, and though Sarah and the Brigadier are closer they’ve both taken several steps back and are visibly leaning away. Everyone is staring at them, minds almost blank from shock, which is quite the overreaction, considering none of them are looking at anything they haven’t seen before.

But despite that shock, despite the undertones of fear that lie just beneath it, there are still no guns drawn, no reinforcements summoned, no sign that UNIT is treating them as an enemy. The Brigadier is the first to recover, blinking, shaking his head, visibly reapplying his professional mask, and finally saying, “Well, that certainly makes things easier. Will you require any further assistance?”

They pause for a moment. There’s obviously nothing the humans can do to help carry the moult, but some loose threads still remain… “Could you get them,” they gesture at the soldiers, “to come and wait over here?”

The Brigadier raises an eyebrow, but complies, spinning on the spot to bark at the soldiers and thereby bringing them close enough the Doctor doesn’t have to stretch to reach their timelines. They immediately get stuck into that, rethreading time across gaps in their pasts, unravelling hopeless tangled causality loops, shaking the occasional bit of carapace out of their potential futures. The soldiers mill around with a nervousness that rapidly turns to confusion; of course, they are completely incapable of sensing what the Doctor is doing with their timelines. While their main body is occupied with that, they make every human in the vicinity jump by abruptly lurching for the trailer. They manage to scramble inside in an at worst modestly embarrassing fashion, and stare down at the last remaining loose end.

It’s their tridimensional limb, their old one. For something that’s been in the midst of a flailing pile of awkward points and sharp edges for the best part of a day it’s in remarkably good condition, almost no bones jutting out at angles they really shouldn’t at all! Of course, that may be because UNIT’s seen fit to clean it up, laying it out carefully on the trailer’s bed in a fresh change of clothes with its arms crossed and its eyes closed. The Doctor grins fondly at the sentimentality of it all.

Then they kneel down and haul it up, hoicking it around their shoulders in such a way that they can keep it in place with an arm around its legs and a hand on its wrist, its head dangling around their other forearm. It squishes ominously as they do so, and a small volume of blood drips down their back, but they’ve just had an object lesson in why one generally doesn’t take tridimensional objects into the higher dimensions, and besides, it’s not far to the TARDIS.

With more effort than they’d usually need but less than they would have ten minutes ago, they hop back out of the trailer. The wounds in the soldiers’ timelines are fresh enough the timestream readily flows back into its prior form as soon as it’s given the chance, so fixing it is proving less fiddly than they’d feared. Just a few little touch-ups, and they can head back to the TARDIS. Their gaze idly drifts towards their friends –

Who are staring at them with a disgusted horror several degrees more intense than anything the Doctor’s picked up from them today. The Brigadier’s face is frozen still, and Sarah’s hands are clasped over her mouth, struggling to breathe. Even the soldiers feel markedly uncomfortable, fighting the instinct to edge away. Their gazes are locked on the body slung across the Doctor’s shoulders, and the Time Lord themself realises they’ve made a terrible mistake.

Slowly, gently, they let the body down onto the tarmac, trying and mostly succeeding at making sure it doesn’t slide or snap. The Brigadier is less successful than usual at smoothing down his emotions, breathing in hard and studiously looking at anything but the corpse. But Sarah is even worse off; her whole body is shuddering, her eyes are shut, and tears are slowly rolling down her cheeks. They close the distance between them without thinking about it, kneeling and reaching out a hand to her. “Sarah Jane,” they say softly. “There’s no need to -”

“Don’t come near me!” she snarls, voice choked, and their hand falls back to their side. Her reddening eyes open a fraction to glare at them, and she takes two long steps back. “You can’t –” She heaves for breath. “You’re going around and being a nuisance and talking to the Brigadier and helping like this is just another day, like nothing’s different –”

Her voice cracks, and while she’s swallowing air, the Doctor takes the opportunity to say their piece. “But nothing is different! Everything you’ve seen today has been part of me the entire time. Just because you didn’t know about it -”

“But why didn’t you say anything?!” Sarah screams. Her mind spikes with a vicious stew of terror, confusion, and hurt, channelled outwards as searing rage. The words blast through the air, the silence that forms in their wake almost deafening. Sarah heaves for breath, fists balled, eyes streaming, and the Doctor wants to move but somehow they just can’t.

After 8.63 seconds of intolerable stillness, the Brigadier coughs. Face and mind wrinkled with what might almost be concern, he reaches out to Sarah and starts to say something, but she cuts him off with a swipe of her hand. “I know,” she says, more to the tarmac than anything else, voice on the verge of shattering. She takes long, deep breaths, gulps in saliva, wipes her face with her sleeve. All the Doctor can do is wait for her to be ready.

Once she is, she looks them directly in the eyes. “I’ve always known,” she continues, her voice measured but still wavering, “that there were things about you you’d rather keep to yourself. I can understand why you wouldn’t want to advertise…” Her left hand jerks around noncommittally. “All of this on twentieth-century Earth. But…” Another deep exhale, a long, slow blink. “Nobody here had even the tiniest inkling about any of it! Everyone at UNIT thought you were just another humanoid alien – wired up differently on the inside, certainly, but still shaped like one of us! Only you aren’t, and you never were, and you just hid that from everybody!”

Her eyes squeeze shut. “We’ve been on all these adventures together, and you’ve been working with UNIT for years! But you never told any of us anything about what you really are. You never even hinted at it. I thought you trusted us.” Her voice shrinks to almost a whisper. “I thought you trusted me.”

They terrified her, the Doctor realises. Partially by suddenly being larger and spikier and more alien than they ever let on, yes, but also by throwing the entire basis of their relationship into doubt. If they weren’t honest about this, were they ever honest about anything? Were they ever really friends? Or were they only ever toying with her, a shallow and easily-forgotten distraction?

In all the infinite vastness of time and space, there is nothing they can think of that could be further from the truth. But how to convince her of that? They’re always at least casually manipulating the timestream, always examining the possibilities and nudging the timelines into a convenient shape, but this is going to require some delicate work. Perhaps a tad more delicate than the nearby timestream can currently support, but the potential for damage if they say the wrong thing is far too high. They’re not going to lose her yet.

Spindles working into the fabric of time, cirri feeling out the branching probabilities, they begin to weave their perfect future.

“Sarah Jane Smith,” they say. She blinks in surprise, like she hadn’t expected them to answer her. “There is no one in the universe I trust more than you.”

That makes her startle with surprise. Her face immediately folds into a scowl, mind rattling with annoyance and a slowly growing offended indignation. She very plainly doesn’t believe them, which is a shame.

For once in their lives, they’re being entirely sincere.

Sarah folds her arms like a police officer about to ask irritating questions about who they are and how they got in here. “Really,” she states, voice completely flat.

The Doctor beams at her. “Really! You know, I don’t let every Tom, Dick, and Harry –” They gesture dismissively towards the soldiers, who – appear to be doing something with their old tridimensional limb, but they can deal with that later. “– I happen to come across aboard my ship. I certainly don’t go travelling with just anybody! I’ve welcomed you into my home, I’ve shown you my favourite parts of the universe, I’ve trusted you with everything important to me.”

Sarah raises an eyebrow, and the Doctor’s eyes soften. “Honestly, I have. You’re curious and kind and brave and just, and I feel honoured to call you my friend. The number of dimensions I happen to exist in is…” They flash a quick grin. “Thoroughly irrelevant. I’ve saved your life, and you’ve saved mine. That’s all that matters.”

Sarah is still scowling at them, but her gaze is markedly less heated than before. She’s still annoyed and a little unsure, but better annoyance than panic. Better annoyance than despair. “You still haven’t explained why you never said anything,” she points out archly.

“Well…” They roll the word on their tongue. “It’s a rather unusual topic of conversation, wouldn’t you say? Rather awkward to bring up out of nowhere. One’s never quite sure how to go about talking about it.”

Sarah rolls her eyes. “As if that’s ever stopped you.” She lets out a long low breath, the high peaks of her agitation smoothing down, just a little. Her gaze is still suspicious, but it’s also thoughtful. The Doctor can tell the exact moment she reaches a decision. “Show me.”

They’re not as surprised as they would be if they didn’t have cirri all over the potential outcomes of this conversation, but they’re still a little surprised. “Excuse me?”

“Show me you. The real you. Show me all of your… Additional parts. Tell me what they do. Explain what you really are, what a Time Lord really is. If you trust me as much as you say you do, you shouldn’t mind answering a few questions.” Her eyes crinkle, and her breath stutters. “Please.”

The Doctor… has to think about this. Their immediate instinct is the same as it’s always been, to fold their wings around their secrets and hide anything that could potentially be used to hurt them. They know how humans can get around the unknown, they’re fully aware that faced with their utter inhumanity, Sarah might reject them outright. Throwing her off the scent with a few carefully chosen lies would, without doubt, be the safest course of action.

But. Sarah is willing to trust them. She’s actively giving them a chance, letting them prove how much she and her friendship mean to them. And they do love her, they do, she shines brighter than any star in the galaxy, she explores and laughs and faces down evil with them, she’s everything they adore in their companions. They want to keep travelling with her, and they can tell from the timelines that this path is the one most sure to lead to that.

Besides, they’re not the only one taking a leap of faith. They’ve just shown Sarah that they’re a totally different sort of being than she thought she was, more alien than anything she’s ever seen, and she’s still reaching out a hand through the unknown to them. There’s got to be part of her that’s wondering if they lied about everything, if they were only ever just toying with her, but she’s willing to put that aside and let them show her otherwise.

In the face of that courage, in the face of that faith, what can the Doctor do but reach out an antenna to brush against her hand?

“No, I wouldn’t,” they answer, tone light and amicable. “Whatever you’d like to know about, I’ll explain.”

Sarah – freezes. For a full second, she just stares at them, mind blank with surprise. Then her breath catches and her eyes widen, and a full, beautiful smile spreads across her face. Relief sparks in her mind, not erasing the tension but, for now, drowning it out with a tidal wave of hope. “Thank you,” she whispers, voice creaking again, but for the first time today her eyes are filled with light.

“It would be my pleasure,” the Doctor replies, beaming in return. They slowly stand back up, drawing their spindles out of the immediate future and working a couple into Sarah’s timelines, back where they belong. “But would you mind terribly if we saved the demonstration for the TARDIS? These ‘additional parts’ of mine aren’t quite designed for navigating the three-dimensional parts of the full universe.” And there are several humans around who they do not trust as much as they do Sarah Jane Smith, but why shatter this moment for such a trifling reason?

Sarah’s brow furrows, but she nods. “All right.” Then – wonder of wonders – she reaches out a hand to them. “Friends?”

They shake her hand. “Friends.”

A quiet cough draws the Doctor’s attention to the fact that a universe exists outside the pair of them. “Is that everything sorted, then?” the Brigadier asks, the left side of his lip quirked up. The turmoil beneath his forcibly calm surface hasn’t gone away, but it never does. It’s the particular kind of light turbulence it settles into once all the excitement’s over and the only thing left is the paperwork.

Well, that’s not their problem, the Doctor thinks as they scan their surroundings for the things that are. The soldiers are milling around awkwardly on the other side of the trailer, being checked up on by a medical officer the Doctor immediately puts out of their mind. Their timelines are healing nicely, and after a couple of quick touch-ups the Doctor concludes they’ll be fine. Their old tridimensional limb is – stuffed into a body bag and laid out on a stretcher, how convenient. “It seems so,” they conclude, quickly glancing at Sarah. When she doesn’t object, they start walking towards the stretcher. “I’ll just be taking –”

“No, you won’t.” The Brigadier steps right in their path, wearing his usual unimpressed stare. “You collapsed on your face not fifteen minutes ago. We’ll take it.” He nods to the medical officer, who comes over from the other side of the trailer, and while they’re picking it up the Doctor dismisses the soldiers with an extravagant hand gesture.

And then they set off. Their little procession heads for the nearest door into the building, the Doctor leading the way, putting one foot in front of the other with very little conscious effort, Sarah walking beside them, her face scrunched up as she visibly thinks of questions, the medical officer and the Brigadier bringing up the rear, carrying the last part of their moult just close enough it doesn’t yank on the rest. “Out of curiosity,” the Brigadier asks, in a tone so casual it has to be feigned, “what are you going to do with all this?” He nods towards the body bag.

“I haven’t quite decided yet,” the Doctor muses off-handedly. The Brigadier blinks, and then sighs, and Sarah rolls her eyes fondly, but the Doctor ignores them in favour of turning the question over in their head. Their second moult was never under their control, of course, but they can’t quite remember what they did with their first. They think they stuffed it into a somewhat withered channel off the TARDIS’ xylem to hide it from Ben and Polly, then…

Then they don’t ever remember picking it up. It’s still there, isn’t it.

Oh dear.

(The TARDIS virtzes with laughter.)