Series summary: When he was a child, Loki got a visit from a man who told him that he was a time traveller, and that they would meet many times throughout the prince's life; but he wouldn't always look the same, nor hold the same company. And, many times throughout the prince's life, that's exactly what happened.

Disclaimer: Don't own Doctor Who or Thor

Chapter 1 – This Left Feels Right

There was a lull on the TARDIS. Such things weren't uncommon – much to the Doctor's irritation – but it couldn't be all flying around time and space and getting shot at by whichever alien race they had managed to piss off that day. Sometimes the adventures just… stopped. There was rarely any rhyme or reason to it; it just sort of happened.

That's what had happened that day.

The TARDIS was in flight, somewhere in deep space, only using enough energy to stop it from being pulled off somewhere dangerous by the gravity of some large celestial object as it floated peacefully passed them all. Its three passengers were sitting around in the control room, all pre-occupied with solitary activities, leaving the ship was in an almost eerie silence.

Jack was sitting on the sofa next to the control panel, fiddling with some kind of 51st Century technological gadget – he had informed them all that it was meant to be a communications device, but Rose had laughed at that and told him that if that was what passed for mobile phones in the 51st Century, then they should never have been allowed to leave the 1980s.

Rose was leaning against the railings, her arms folded over her stomach and her eyes glazed over as she stared into space, the sound track of her introspection being the occasional sparks, clunks and Gallifreyan profanity coming from the long pair of legs sticking out from underneath the grating.

The Doctor was… well, neither of them were entirely sure exactly what the Doctor had been doing for the last hour and a half, but he was working on something with the sonic screwdriver, and so they had decided that it was perhaps best to just leave him alone to get on with it; after all, neither of them wanted a repeat of the time when Jack had snuck up on the Doctor with a feather duster while the Time Lord was trying to reconfigure some settings on the scanner, and he had very nearly ended up depositing the ship into a volcano. And so, as always, the Doctor's occupation was the first to end.

It began with a faint burning smell – so faint that neither Rose nor Jack really noticed it. Yet it grew steadily stronger as the seconds passed, and the buzzing of the sonic screwdriver became more and more frantic.

The change in pitch of the alien instrument was enough to draw Rose from her reverie. She blinked once, returning to reality, and looked down at the Doctor's legs, sticking out from underneath the floor panels.

The appendages were twitching slightly now, as though the Doctor was trying to push himself further into the ship to sort out a wire or a circuit or a fuse that he just couldn't reach.

This strange display lasted for a few moments before a soft, swirling cloud of smoke began to rise from the opening in the grating, like a candle had been lit somewhere directly below it. The Doctor, however, seemed oblivious to that fact, and continued with his tinkering.

An uneasy feeling welled up within Rose. She slowly unfolded her arms and wrapped her hands around the bar of the railing behind her, leaning forward slightly in the hope that her Time Lord companion would be able to hear her better.

"Doctor?" she called warily, yet the only person whose attention she drew was Jack's: the former Time Agent finally looked up from that sad excuse for a mobile and surveyed the scene before him, from the worried Rose and the Doctor's non-listening legs, to the plume of smoke that was growing steadily thicker with each passing second.

Jack put his strange device down on the sofa seat next to him and pushed himself to his feet, his thick boots clunking on the grating as he walked over to the Doctor.

"Doc…" he said warningly, but to as much avail as Rose.

It was now becoming difficult for either of the humans to see the hole in the floor into which the Doctor was half-inserted, for it was almost completely obscured by smoke. Jack looked ready to grab the stubborn alien by the heels and drag him out of there, regardless of what he might have been up to at that very moment, but he was relieved of having to do so when there was a small puff and thick, black smoke flooded out of the hole.

The Doctor emerged quickly, slightly soot-stained on his face and hands as he made a hasty retreat from his workspace, coughing as he waved a hand to clear the cloud that surrounded him. When he had recovered, he looked up to see Rose and Jack glaring at him.

Rose even had her hands on her hips.

"What?" he asked innocently.

"What have you done?" Jack asked impatiently. "Have you blown something up?"

"No!" the Doctor insisted, but neither of his companions looked all that convinced. The Time Lord sighed, tucking the sonic screwdriver into his pocket and pushing himself to his feet. As he turned to the control panel, Jack replaced the square of grating that the Doctor had removed to fit underneath it.

The Doctor was tapping away at buttons on the console as the screen on the scanner flickered. Gallifreyan symbols appeared on the screen and disappeared again almost immediately. The Doctor took them in with his fast-moving eyes, the smile melting slowly off of his face as he read.

It did not go unnoticed by Rose.

"What is it?" she asked, moving around the control panel to stand next to the Doctor, but she couldn't understand the alien script.

"Nothing," the Doctor replied quickly, with a shake of his head.

It was a terrible lie.

"Doctor," Rose snapped, in the tone of voice that made her feel as though she was the Time Lord's mother and he was a child refusing to go to bed. She was still glaring at the Doctor when she felt Jack stand just behind her.

"I haven't done anything," the Doctor explained. "The TARDIS has."

"And what has the TARDIS done?" Jack asked impatiently, crossing his arms over his chest.

A dark look crossed the Doctor's face momentarily – so swiftly that if you blinked, you would miss it. It did not go unnoticed by Rose, who felt a sense of unease at the sight of it.

It was known to all on board the TARDIS – but entirely unspoken – that the Doctor wasn't entirely happy that Jack was travelling with them. Up to their trip to 1941, the dynamic on the ship had remained mostly unchanged since Rose had agreed to join the Doctor on his travels. There had been the brief period when Adam had joined them, but after the incident with the boy genius nearly messing up the entire timeline of the universe, both the Doctor and Rose had decided that his inclusion on the TARDIS had been a bad idea.

Jack, on the other hand, hadn't done anything quite as devastating as that. Granted, he had tried to con the two of them and had nearly killed all of East London before the Second World War had even ended, but since he had come aboard the TARDIS, he had mellowed.

Somewhat.

He had certainly never tried to con them again, and early-1940s London had never been safer – except for the bombs, that was.

Even so, his presence and the rising of the population aboard the time ship from two to three (or three to four, depending on if you counted the TARDIS itself as a sentient being, which the Doctor always insisted upon, but Rose remained sceptical about) had never particularly sat well with the Doctor.

He never said anything outright – though the double-meanings in his words towards the ex-Time Agent sometimes forced Rose to suppress a wince – but it was obvious that there were times, not necessarily all the time (but definitely some of the time), when the Doctor resented having Jack with them. It wasn't as though the two of them didn't get on, or even that they had any ill feelings towards each other at all; but there was still a rivalry between them that Rose didn't fully understand: a rivalry that always seemed to reach an uncomfortable peak whenever Jack said or did something that the Doctor took as an attempt to assert a superior level of authority.

"The TARDIS," the Doctor began, his voice hard as he swerved on Jack; he turned to Rose and his expression softened, "has turned off the Odyssey Facilitators. She wasn't happy with me tinkering."

"Well, can't you turn them back on again?" Rose asked, waving her hand ambiguously at the panel. Surely there was a button or a lever or a widget or a gadget on there that would override the TARDIS' decision – whatever that decision, in fact, entailed.

"I can't," the Doctor replied gruffly, shooting a brief look towards the now blank scanner. "Have to wait for the TARDIS to calm down and turn them back on herself."

"But until then, we're stuck here?" Jack asked, disbelieving and indignant. He leaned forward slightly, his arms still folded over his chest.

"No," the Doctor told him. "The Odyssey Facilitators can't be turned completely off. There's a safety mechanism which prevents it, so that if any danger befalls the TARDIS and we need to get away quickly, we can. But when they're off, that's all we have: one journey. Then we have to wait for them to turn back on."

There was a brief silence that followed the Doctor's words as they sank in, until it was broken by Jack.

"So where do you wanna go?" he asked, unfolding his arms and looking from the Doctor to Rose.

Feeling slightly ganged up on – as the Doctor turned to face her as well – Rose stammered slightly, not quite sure who to look at. Jack had an eager look on his face, obviously desperate to go off somewhere and have an adventure. It had been a while since they had properly done something other than just sitting around in the TARDIS as the ship floated through deep space, and she was rather looking forward to the next time that they would be somewhere else and actually doing something – even if that something didn't involve saving an oppressed alien race on some far-flung planet.

But then she looked over at the Doctor, and he had that dark and shadowed look on his face that he wore when he thought that someone was going to make a bad decision that he might not be able to rectify.

"Uh…" she hummed. "Is it such a good idea to waste our one trip? I mean, we might need it."

"We're in the middle of nowhere!" Jack exclaimed impatiently, turning fully towards her. "Nothing's gonna attack us out here, and we don't know how long it'll be before the Facilitators turn back on. What are we supposed to do until then?"

"You could always go to the library," the Doctor said in a mock-cheerful tone of voice, prompting a scowl from Jack.

Rose could see that a compromise would need to be reached, lest she end up the reluctant referee in another one of the Doctor and Jack's bitch fights.

"Well… how about we go somewhere we know is safe? Like the Eye of Orion, or-"

They were cut off by the familiar sound of the TARDIS taking off: the loud groaning and wheezing that filled the entire ship as the time rotors in the central cylinder that ran upwards from the console began to move up and down.

"What's going on?" Jack asked tentatively.

The Doctor turned back to the screen, tapping away furiously as though trying to override some command.

"The TARDIS is sending us somewhere," the Time Lord explained. "She's obviously got plans for our one trip."

"Well, where are we going?" Rose asked, her voice a dark almost reminiscent of her mother. She crossed the space between her and the Doctor to stand at his side, looking up at the screen and the string of numbers and letters written upon it.

"There," the Doctor answered, pointing at the screen.

Jack took his place on the other side of Rose, gazing upon the screen.

"That's on the other side of the galaxy," he noted, looking over at the Doctor. "What even is there?"

"I don't know," the Doctor admitted, "but I know who we'll find there."

The Time Lord reached into the inside pocket of his leather jacket, retrieving a piece of paper that had a line of red handwriting upon its yellowing surface. The characters had almost faded away, but as he angled the paper towards Rose and Jack, they could still make out enough of what was written there to know that it was the same line of numbers and letters that was on the TARDIS' screen.

"I've had this for a while," the Doctor explained.

"I think that might be underestimating it a bit," Jack commented, but the Doctor ignored him, instead looking Rose straight in the eyes.

"Loki gave it to me."

Rose's eyes widened as Jack's brow furrowed.

"Loki?" the ex-Time Agent asked.

"Prince of Asgard," the Doctor answered. "We've met him before," he added, gesturing to Rose with a slight nod of his head.

"He was in prison," Rose told Jack.

"But he wasn't when he gave me these," the Doctor interrupted, tucking the paper with the coordinates on it inside his pocket again.

The familiar wheezing sound of the TARDIS being in flight began to die down as they landed… somewhere.

"Well, where does he want you to go?" Jack asked, as the Doctor turned and headed for the door. Rose followed quickly, practically on his heels.

"Dunno," the Time Lord admitted. "Those coordinates aren't on Asgard, though they're closer to Asgard than they are to Earth. Then again, knowing Loki, we could be anywhere."

The Doctor wrenched the door to the TARDIS open, and made to take a step outside.

"Doctor!" Rose screamed, as the Time Lord's foot found no purchase and he nearly fell out of the ship. Rose grabbed his arm and steadied herself by holding on to the doorframe as the Doctor half-hung out of the TARDIS, one arm flapping uselessly as he tried to right himself again. With a strong pull, Rose yanked the Doctor back into the TARDIS, earning a grateful nod as the Doctor looked out on where they had arrived.

If it had not been for the fact that the TARDIS had made the whole song and dance about the fact that they were definitely in flight, Rose thought that she wouldn't have believed that they had moved at all: the black- and blankness of space still stretched out before them, as far as the eye could see, not punctuated by any kind of star or planet for millions of light years.

"Where are we?" Rose asked, stepping back slightly from the doorway.

"I have no idea," the Doctor mumbled, looking out of the door from the left to the right and back.

"Why would Loki want us to come to the middle of nowhere?" Rose wondered aloud.

The Doctor didn't reply, now half-hanging out of the door – with one hand gripping the doorframe so that he didn't fall out – still searching the emptiness of the space outside the ship for some clue as to why the trickster would have wanted them to come here.

It was only when he looked up that he finally realised.

There was something – a single, solitary body – in the vast nothingness of this area of space, which was gently floating towards them.

"You've got to be kidding me," the Doctor sighed, reaching out his hand for the body as it got closer and closer.

"What is it?" Rose asked, but her question was ignored.

A few moments later, Loki's hand was within the Doctor's reach. He grabbed hold of it and pulled the trickster inside the ship, setting him up on his feet.

He looked a lot younger than he had the last time that Rose had seen him, with shorter hair that appeared to have been taken greater care of, and instead of a rather every-day and Earth-like outfit, he was wearing what was obviously the height of Asgardian finery: gorgeous greens and golds and blacks with long, flowing materials and shiny, metallic finishes.

But for all the strength that his attire suggested, the man himself did not appear nearly as stable.

His skin was as white as a sheet, in stark contrast with his dark hair. He appeared to be quite thin – though he had always been quite thin – and his cheekbones were almost visible in a way that didn't seem entirely healthy.

His eyes were closed when the Doctor pulled him inside the TARDIS, but they slowly fluttered open when he seemed to realise that he was no longer floating in emptiness. Their usual bright green was dull and hazy, glazed over as if they hadn't seen anything other than blackness for longer than Rose cared to think about.

They flickered slightly as his eyes fell on the man standing before him, a shot of recognition flashing through them.

"Doctor?" he croaked, his voice barely louder than a whisper, before his eyes rolled back into his head and his knees gave way underneath him.

The Doctor caught him by the arms before he collapsed fully to the ground, but it was perfectly clear that he was no longer conscious – and possibly wouldn't be for a while.

From somewhere near the control panel, Jack sighed.

"Why do pretty boys never collapse into my arms like that?"