Many years down the line, Jungkook will be annoyed that of all the days Jin could have crash landed into his life, he picked one so very long ago. Small children don’t remember things so clearly, you see, and what memories they have struggle to last through to adulthood.

He had been very young - five? Maybe six? - when the night skies opened over the park at the end of his road, and a blue box tumbled out of thin air onto the asphalt. Jungkook had been watching from behind the swings, his heart thumping a mile a minute. He remembers being scared, but more because he didn’t want to be caught sneaking out of bed than anything else.

He remembered the sound of the box opening, the sound of the machines inside screaming. He remembered stars.

(The box didn’t fall out of nowhere, it fell out of time)

The man who had staggered through the door had been brilliant and blazing. Literally. Sparks struck the Earth where he trod and as his eyes met Jungkook’s through the dark it was as if the whole universe was contained within them.

The man had smiled, “hello there! Sorry about...this...”

It had looked like an effort to talk, and when the man had turned to look at the box he had clutched at his sides like his ribs were broken. Jungkook swore he could remember hearing him gasp in pain but he thought that they were probably too far from each other for the sound to carry.

“You should go,” the man said, as the door to the box swung closed of its own volition. He looked back over his shoulder with gold shining below his skin.

Curiosity kills more kids than cats, and Jungkook had been rooted to the spot. Scared and excited all at once. Sometimes he wondered why he didn’t just run - surely charismatic strangers in dark parks are enough to scare a child witless - but he had stayed.

A crack split the air like lightning, for a moment the ground seemed to fall away, and then the man exploded in a sea of sparks.

Jungkook had run, out of the park, down the street and through the front door so fast that he never stopped to wonder if he had shut it hard enough to wake his parents. No one says anything the next morning though, and the blue box is missing from the park.

Jin left nothing, not even scorch marks. Years later Jungkook would learn that he didn’t die that night, but he changed.

 

He’d run from the Cybermen when he was seventeen, hadn’t wasted any time when he’d seen them first marching up out of the water on Haeundae, just fled. He hadn’t needed to see more, hadn’t needed to know what the strange metal men rising out of the ocean were for, Jeon Jungkook knew the smell of danger and he wanted nothing to do with it.

The trouble with running in Busan is the hills. The city rises and falls no matter which direction you head in, and no matter how fit you are, when you’re running fast enough to save your life, it’s exhausting.

Still, Jungkook made it a couple of miles before he ran out of steam, crashing to the ground in a mess of limbs, breath shaking. He could hear the screams wafting up from the beach, along with a terrible rhythmic clanging that he didn’t need to think hard about to guess was the pounding of metal feet on the streets.

“Ah! There you are!”

Jungkook’s head whipped round, trying to trace the source of the voice. Eyes eventually falling on a face peering round the corner at the end of the alley.

He blinked, “do I know you?”

“Of course you know me! It’s me, Jin!” Jin had smiled, and the faintest memory of stars crossed Jungkook’s mind.

He didn’t know what to say, but he let Jin examine him at the end of a small metal rod that made strange sounds and flashed too bright in his eyes.

“You look alright, are you feeling alright?” Jin asked, a hand on Jungkook’s shoulder that was far too familiar for first contact. He wanted to shrug him off and tell him to get lost, but he wittered on about the metal men from the sea in a way that made it sound like he knew how to handle them and Jungkook wasn’t in a position to turn that down.

“I’m...” exhausted, he wanted to say. But Jin’s eyes were expectant and the tension in his posture that of a man who was ready to run, “I’m fine.”

Jin had dragged him up and down hills, through backstreets and shortcuts, till they came to a blue box tucked neatly down an alley.

“We’ve gotta go back a little for this one,” Jin grinned, “you don’t mind, do you?”

Something that sounded suspiciously like someone having their lungs ripped out echoed through the streets. It sounded close, way closer than the metal men had been when they were running. Jin was still smiling, like he didn’t hear or didn’t care.

The door to the box swung open and Jin ducked inside. The thought occurred to Jungkook that anything could be awaiting him inside that blue box. That Jin should really be older than he looked by now, given how long ago it was that he last saw this box.

And it was this box.

Jungkook took a long, shuddering breath. Stupid of him, how dumb did he have to be? A man with a face he hadn’t seen in ten years pokes his head into his life and he just ran off with him because...because he was scared?

“Get in then,” Jin barked, one foot still outside the box.

“The last time I saw you, you exploded.”

Jin'ss face resolved into understanding, “We haven’t done this before...”

“If by ‘this’ you mean ‘get caught in the middle of a robot invasion’ then yeah, we haven’t done it before,” Jungkook snapped, fingers twitching into fists at his side.

The sound of metal creaking and snapping from behind them came uncomfortably close. Jin held out a hand, “Just get in, please. I’ll explain everything.”

Jungkook ignored the hand, but when the sound of buildings crumbling away to nothing shook the ground beneath his feet he followed Jin into the box, slamming the door behind him and feeling it lock itself.

The strangest sound reverberated around them, a rushing, beeping, whining sound that his memory could just about make sense of. He had forgotten he even knew that detail. Jungkook turned to face Jin but found his fury dying on the outskirts of his thoughts as he drunk in the sight of the interior of that funny little blue box.

It was bigger on the inside.

 

The Daleks came as something of a shock, but by then Jungkook had seen enough killer aliens and plots to destroy the universe to not let it shake him. They landed in New York and he took the first flight out of Seoul to meet them.

(It was the last outbound flight between Korea and America, and when he transferred in LA only two other people boarded with him)

He had heard tell of these metal monsters that had purged themselves of emotion in their attempts to become the dominant military force in the universe, but he hadn’t been able to appreciate their ruthlessness till he saw a troupe of them tear down Fifth Avenue and kill every living thing in sight. It left Jungkook scared, it left Jungkook angry.

“Why are they like this?” he had roared when Jin finally showed up, three days late by everyone’s reckoning and entirely too spry for someone who claimed to have been alive for over eight hundred years.

Jin had smiled his saddest smile, flicking through a box of worn out electronics and old weaponry, “we made them feel weak, forgive me.”

Jungkook’s has heard the story of the Time War three times by now, but Jin will only be able to remember all the times he’s spelled it out in his past.

Jin’s past, Jungkook’s future. They both know the drill by now.

“Have I taught you how to use the sonic yet?” Jin has asked, throwing the little stick with it’s flashing lights and strange noises straight into Jungkook’s hands.

He learned how to use the sonic screwdriver when he was twenty one. They were paint-balling on Neptune, thirty thousand years in the future. It was one of their less stressful escapades.

Jin took on the Daleks singlehandedly that time, strode right into Central Park like he might not be killed. He said something to them though, something so terrible that they just left. Blasting off into the depths of space without as much as a backwards glance.

People had thought it was the end, Jungkook supposes it could have been, for Earth, but not for Jin. Jin still had all those years to go until he scattered into his component atoms in the park on the street Jungkook used to live on when he was very small.

Jungkook and Jin had gone back to that funny little wooden box together, the TARDIS, as he now knew it, and Jin had offered him a lift home.

“Can’t I come with you this time?”

“Not today, Jungkook. Soon, I promise.”

It had been three years previously that Jin had last shown up on Jungkook’s doorstep. He had insisted on a month long tour of the Vogon Nebula way out in the Persephone galaxy. That made a whole lot more sense in hindsight.

Before the TARDIS blinked out of existence in Jungkook’s living room, Jin had asked him how old he was, and it was impossible to miss the expression of apologetic sheepishness that flashed over his face when he was told, “thirty four”

“It’s gonna be a long time before I see you again, isn’t it?” Jungkook sighed.

Jin smiled sadly at him as the TARDIS door swung closed, “forgive me.”

He always did love feeling guilty for other people’s mistakes.

 

From the moment they landed, Jungkook knew this planet was special.

“What’s out there?” he had grinned at Jin across the control pod. He had remembered how to drive the TARDIS after all this time, like a large, sentient, time travelling bicycle.

Jin trotted into the wardrobe and pulled a thick fur coat for each of them, “the Ood.”

Jungkook had met the Ood many times throughout the course of his and Jin’s shared history. They were butlers in the houses of bitcoin billionaires, receptionists at high end hotels, bouncers at expensive night clubs. He had assumed they were a race that found themselves best suited to the service industry - he had seen stranger things after all - and never thought anymore of it. He hadn’t known they could sing.

Jungkook stepped out onto the snow of the Ood homeworld and felt the music tear through his chest, fill up his lungs and drown out his heart. It was so sad, so happy, so all emcompassingly beautiful, he had wanted nothing more than to join in but he didn’t know where to start.

“My god...” he whispered. He didn’t realise he was crying till he saw the tears on Jin’s cheeks.

The Ood had crept out of drifts and buildings, approaching cautiously till one of them recognised Jin and as the cry went up that the Last Timelord was amongst them they shuffled forward in an enthusiastic huddle, still singing their eerie, immaculate song. Each one of them had their hands pressed together, like they were holding something precious - Jungkook was sure their speech orbs were missing.

“They hold their brains,” Jin replied, when they were back on the TARDIS and the music was fading into memory, “the other ones you’ve seen have been...modified.”

Jungkook’s blood had run as cold as the snow on the surface of the planet outside, “what do you mean?”

“They were enslaved, sold across the universe for years. Traders would cut off the brain and replace it with those speech devices to stop them singing. I thought I’d take you to see them as they should be seen.”

There’s nothing quite like finding out that the world you’ve come to know and love is built on lies. Jungkook tried to remember every time he had met an Ood in his life, all those times he had thought he was being kind when he thanked them or spoke to them or tried to treat them like they were as good as the people they worked for. He hadn’t known the first thing about what they were going through, he hadn’t the faintest idea how to really help them.

“It was you who freed them,” Jungkook didn’t need to turn it into a question, and Jin didn’t need to nod for them to both know it to be true.

Jin had fiddled with the controls and huffed over pages of Galllifreyan writing, and pointed out that the Ood could only have freed themselves, he just helped them along.

(Jin said Gallifreyan was a hard language for humans to learn how to read, Jungkook had laughed and pointed out that it was just like Hangeul)

Jungkook stepped out of the TARDIS two blocks from his apartment, and only then did it occur to him that Jin had no idea where he lived. That was all in his future.

“Wanna come in for some food?” Jungkook had asked, laughing at the over enthused joy spreading across Jin’s face when he said yes.

Jin’s eyes had looked young that night. Older than any human he’d ever met, perhaps, but Jungkook didn’t miss the way that sparks flew across that oh so familiar face. He couldn’t help thinking about the night he had first looked into it and seen the universe.

“You’re getting so young,” he had laughed. And I’ll soon be so old, and that face of yours will never change.

 

There had an irksome crick in his back and spring in the air on the last day. Jungkook had been out for a walk, muttering under his breath about useless friends who didn’t know the first thing about his bones and determined to prove every last one of them wrong. He had moved back down south not so long ago, not quite into Busan proper but into the countryside that surrounded it. He tried to persuade himself that his growing impatience with the inner city was not a symptom of senility and brushed his greying hair under a hat.

Just last week he’d found an old Cyberman head stashed under a rock out in the woods, he’d trodden slowly after that, the city had a lot of forgetting to do before they could overcome that collective nightmare.

There had been a man standing down by the stream where Jungkook was determined to establish a daily run just as soon as his damn back sorted itself out. He had been clutching his ribs like they might be broken and electricity crackled at his feet.

Jungkook in air sharply. This was all too familiar, he had seen this before. Everything, from the gold glistening all around them to the threat of thunder hanging over their heads.

The man looked at Jungkook over his shoulder with a weary sort of smile, “hello there! Sorry about...this...you should get out of here.”

This time, when the man exploded, Jungkook didn’t run. He needed to know how this ended, what had happened to Jin.

The air cleared, the dust settled, Jungkook had to blink against the receding gold rush hammering against his vision. So maybe that was it, scattered into his component atoms, he can only assume Jin took the TARDIS with him when he went.

“That’s much better! Oh wow I’d been meaning to do that for ages.”

That voice! That familiar, reassuring, self-deprecating, forever-young voice! Jungkook caught up with the world and a pair of big brown eyes came into focus, framed by an overly friendly smile.

It was Jin. But the man who had been standing there five minutes previously had not been, surely.

“How did you do that?” Jungkook asked in awe.

“Ah it’s just an old trick of mine. You weren’t really supposed to see me, but what’s done is done. I’m sure you’ll be nice enough not to tell on me.” He’d winked, then started fiddling with something Jungkook was very sure was not a watch, strapped to his wrist.

It was all so very obvious that Jin didn't recognise him. Jungkook had been suspicious the last time they met, just over a year ago now when the Sontarans had come for Daegu. Jin had been cautious, less familiar, like he was just playing along with what he thought was wanted of him.

Jin hurried past him, back onto the main track, “oh well, must dash. Places to be, people to see, you know the drill. I’m Jin by the way, and I really would appreciate it if you didn’t tell anyone about my little...”

“Explosion?”

“Well I mean it’s called a regeneration but whatever works for you.”

Jin held out a hand like he was expecting someone to shake it. Jungkook hesitated, just for the briefest moment, wondering what to tell him. To start at the beginning and go through everything, to tell him just enough, or to say nothing at all?

There was so much locked up in Jungkook’s head, his life scattered across the stars. And here came Jin out of the ashes of another man with no time to explain and no memory of their shared travels. Everything they had ever done together, for him had yet to come.

And so he said nothing, because he’d hate to be a spoil sport. He had taken the hand offered and given it a firm shake, “I’m Jeon Jungkook.”

Just like that, his travels ended. Jin went running off and presumably found the TARDIS and freed the Ood and showed up three days too late for a Dalek invasion and ran him ragged through the streets of Busan and exploded all over again somewhere in Jungkook’s distant past.

Jungkook stepped forward along his timeline with his back straight like it didn’t twinge uncomfortably when he walked. He eyed the news for alien activity, he ran towards danger, he swore he could hear the TARDIS whirring in the distance on quiet days. He remembered stars.