This is a crossover in between Doctor Who and Inheritance. Technically, it isn't a crossover, because Paolini stated at the end of Brisingr "For whoever understood the reference to a lonely god in the campfire scene, my only excuse is that the Doctor can travel anywhere, even alternate realities. Hey, I'm a fan too!" This one-shot describes where Arya got that reference. In fact, there were two references;

-"The trickster, the riddler, the keeper of balance, he of many faces who finds life in death and who fears no evil, he who walks through doors."
-"Adrift upon the sea of time, the lonely god wanders from shore to shore, upholding the laws of the stars above."

To anyone reading this story; I have also created Empire, my ideas on how the fourth book of Inheritance will turn out, and Silence Will Fall, what I think will happen after the Big Bang (besides "A Christmas Carol") and who cause "the voice". Both can be found by turning to my profile page.

So far this story is called The Doctor and the Impossible, and I can't find a better name for it. It is a work in progress, so I might come up with a better name, if not; it won't change. If you can come up with one, I'll include you in the dedications (check my profile page to find them). This is my longest One-Shot or chapter ever with 3753 words! If you need to understand a word, it will most likely be in the afterwords.

Disclaimer: Idea is completely CP's I just tweaked it a bit. Quotes are included from Doctor Who.

Added on the 18th of November 2011:

I read inheritance 10 days ago... Yup, I finished it the day it came out ;) Within I found two more references;

-Solembum says that he has seen many strange things, lists a few, then at the end of his list says, "Rooms that are bigger on the inside than the outside..."
-Angela is knitting a sweater (or hat, I can't remember), red with blue runes, when Roran comes along and, not being able to read, says something, then "It's nice, I like the blue. What do the runes say?" Angela replies this; "Raxicorico- Oh never-mind, it wouldn't mean anything to you anyway." For those who aren't as dedicated, or have no clue of what her finished word was: Raxicoricofalapatorious (homeland of the Slitheen family).

The Doctor and the Impossible

The air in front of Illiamen howled and a shimmering light slowly materialized in front of her. There stood a blue box, with the words "Police Box" outlined on it. The door opened and out came a man dressed in a billowing cloak with a buttoned vest and bow-tie. His hair was fluffy and ginger, and his hands were new and unused, like a grown baby. He ruffled his hair and pulled a few down in front of his eyes. "Finally, ginger! Been waiting four regenerations for that!" Then he spotted Illiamen and rushed to her. "Hello there, I'm the Doctor, how do I look?"

Fourteen Days Ago

Illiamen grabbed her spear and raced to the battling area, ready to train for Du Fyrn Skulblaka, the dragon war. "Illiamen, there you are," said her instructor in the Ancient Language, "Little late, you are. Do a few rounds of the Rigmar and come join us." The Rigmar was a series of poses that prepared the elves for war. Once Illiamen had completed the exercises and had started to train, a war horn sounded just outside of Ellesmera. "The dragons are coming! Prepare for battle!" The elves rushed to the armory, but a magical force pulled Illiamen into an abandoned building.

A shadow emerged from the dark and greeted her. It was the seer, Amorses. "Amorses! We thought you had died in the last dragon raid! We saw your body! How are you here?" Amorses shook his head. "I did die, but I managed to preserve my consciousness in a gem until someone passed by. I need to deliver this warning." And then she passed into a trance-like state, like she always did when uttering a prophecy, but this time she also passed into a gas-like state. "The time has come. The eleventh life ends and another rises, and the Doctor will come! The war with the dragons shall end, and another shall begin, at the hand of the one in the Blue Box."

Ten Days Ago

"But if this... Doctor is coming, he will end the war between the dragons and elves! It's what we've wanted ever since the war started, for them to pardon our mistake!" Said Illiamen. "We need to look for him, to find him before it's too late!"
"Illiamen, let it be! You were probably just worried about the dragons and imagined it, he was dead, we all saw the funeral. Just let it be." Sukwa, Illiamen's sister, rested her hand against Illiamen's shoulder. "Just forget about it."
But Illiamen stood and shook off Sukwa's hand. "No, I will not let it be. I will look in his chambers. He recorded everything he saw, and he hinted that he had seen this long before he died. I need to see."

Nine Days Ago

Illiamen broke the door. The handle had been burned, the debris had blocked it from the other side, so to destroy the wood was the only option. As soon as she entered, she used magic to locate the book that she had been searching for and rifled through the pages. She had to hurry, since they were going to be raiding a dragon's nest soon. She had donned her armour earlier, and had hurried here as soon as no one was looking, but even in all of that, she still only had a few minutes. Finally, she located the last prophecy in the book. The words that Armorses had uttered were there, as well as a fairth describing the location of the arrival. An elf stood in the picture, talking to a man, who had to be the Doctor, and behind him was the Blue Box. "Well, I've seen this glade before, it is near the Menoa Tree. As for timing, the sun is high in the sky. Probably noon. I don't know the date, so I'll just have to sit there everyday."

Present Day

"Hello there, I'm the Doctor, how do I look?"
Illiamen stuttered. She had expected to wait for years for this man to come, yet he had come here so soon. He wasn't even an elf, but rather a much less elegant version of them, or a much taller version of a beardless dwarf. "U-um... Crude. Tall. Ginger."
"Ah, yes, thank you for noticing. Do you have any water? Wait- did you just call me crude? What kind of a compliment is that?"
"It wasn't a compliment."
"Oh, wait. Ears. You have pointy ears. And a chin. Yes... pointy chin... In-curved eyebrows. You-you don't look human. I did land where I meant to, didn't I, on earth?"
"Well, there's earth beneath us. You're in Alagesia."
"Alageasia? Never heard of that. Well, that's new. I just went somewhere I've never heard of. I don't even recognise the smell. Smells a bit... appleish. Yea, smells like apples. Wait a minute, am I having a craving? I don't trust cravings anymore. Last time I had a craving, about an apple I threw it out the door. Should I take a chance? I think not. I say what a-"
"Doctor!"
"Yes, wait- how do you know who I am, do I know you? I don't recognize you. I think I did come to the wrong place. It is hard to steer when you're regenerating, isn't it? I-"
"Doctor!" "
"Yes, yes, sorry, you were saying?"
"Stop talking please."

"So, you heard of my coming in a prophecy, is that right?" He asked. Without saying a word, Illiamen nodded and handed him the fairth. "Well that's pretty. Is that me and you? What type of ink is that?" And he pulled out a small contraption with a green end and pressed the end. The tip started to glow and Illiamen's ears exploded with pain. She double over, covering her ears. "Letta!" The buzzing noise stopped and the contraption's tip's glow faded. "Well, what's wrong with this thing?" He fiddled with it for a moment, went back into his tiny Blue Box, and re-emerged with it again. "There, seemed the sensors were blocked. Wouldn't come out, so I just overloaded the sensors. I'll have to fix it again later, but it won't happen again." The buzzing started again, but instead of re-activating the spell, Illiamen simply snatched it from his hands and threw it as far as she could. "What was that for? I was using that!"
"It was hurting my ears."
"It was barely making a noise! Oh, wait-" And he searched in his pocket before withdrawing another small device, though this one was round with a tip at the end. He pricked the tip against Illiamen's skin -"ouch!"- and examined the device. "DNA reading, not human. I was right. You are... Come on, come on." The gadget exploded, leaving the Doctor's eyebrows singed.
"Well, there's only one explanation for that. Give me one second." He rushed one more time into his Blue Box, and this time emerged with a giant metal object. He was carrying it on his shoulder. "Picked this buddy up when I was in an alternate reality before the Time Lords vanished. It can read - ironically - spacial differences in the fabric of the universe, therefore telling you if you are in an alternate reality. Won't work in the TARDIS because that is technically from my reality, that therefore IS my reality. And-" The machine beeped. "I see, so if I read the atmosphere..." The machine beeped again. "Ooh, but that's impossible." The machine beeped again. "Oh, that makes sense then." The machine beeped again. "Don't call me an oddity! You piece of," He kicked the machine, and it beeped again. "Well so are you!" He picked it up and carried it back into the "TARDIS". He came out again, examined his surroundings, before saying, "I'm in a parallel universe. Who knew that if the TARDIS was damp due to a dump in the everlasting lakes of the Medusa Closure, the result of the closing of the Medusa Cascade, and if I regenerated inside of it, I would be teleported to another universe? Blimey, I need to get out more. Wait- I'm in another universe, out much more 'out' can I get? I've been to Midnight, to the end of the universe itself, to the lost city of Atlantis! I have gotten out. What I need is to-"
"Doctor, I can't understand a word you're saying. Please shut up." He shut up.

Illiamen sat on a rock and thought how the Doctor might have been interested in Amorses book, the book of prophecy. It might just explain why he was here. "Doctor," began Illiamen, "I know a book of prophecy that holds many pictures and words that describe other prophecies. Would you like to see it? I happen to have brought it along today."
"Sure, it might clarify on the prophecy that brought me here." Suddenly, the Doctor collapsed, clutching his chest. Illiamen rushed to him and knelt down. "Doctor!"
"Don't worry, this is all perfectly normal-" and with that he let out a stream of pure energy from his mouth. The feeling of it almost made Illiamen faint in comparison to it's power. Trembling, he managed to stand on his feet. Illiamen was amazed. This man contained so much energy in his body; he could destroy an entire city if but he could use magic. "Doctor... Who are you?" He gulped in air, then calmed his voice before responding. "You know when you're a kid? And they tell you that the earth is actually round and and floating in space, and you just don't believe it because everything looks so flat? I can feel it. I can feel the rotation of the earth, us just barely hanging on, and if we let go... That's who I am. That's all I am, or at least, that's all I know about myself up to date. Now... Where's that book?

Once she had located Armorses' book and handed it to him, she lit a fire, though not with magic. This man was using peculiar words, and to use magic, she sensed would fasinate him more, and entice him to roll out another book of utter nonsense. He turned the pages, revealing more and more prophecies, though Illiamen avoided looking; to look upon a prophecy that she shouldn't see was to change the course of history, or so she assumed. She stroked the fire, and added a few leaves to a stew that she was making. If this man was like a dwarf, or as he said, 'human', then he must like meat, but Illiamen was one of the most caring of all the elves, hence her hatred of the war. She gave the broth one last stir before lowering her hands into the pot. This part required magic, but she couldn't let the Doctor see, so she lowered her hands just above water level. "Astruator." Then, there came a beep. The Doctor looked around and searched in his pocket for yet another device. This object was a simple copy of what he had had before, the round, pointy object that he had poked Illiamen with, but it had no point. Instead a blue transparent glass was where the point had been. It beeped and the blue solidified, then extinguished as the beep ended. "What just..." The Doctor stood up, walked in a circle, then started zigzaging in Illiamen's genral direction. Finally, when he reached her, he shoved his tool into the soup, withdrew it, and dried it on his shirt. "According to this, something with alot of energy came from you," he pointed to Illiamen, "And went into the soup. Do it again. I want to see." She stood up and realized that preventing him from talking was impossible, and hiding her magic was equally as hard. She raised her hand and said "Letta!" The trees and grass stopped swaying. The wind that had buffeted them stopped, and even the ants at their feet froze. Then she said "Brisingr" and a tree in front of her burst into flames. She turned to the Doctor and said, "Magic."

"No, not magic," Said the Doctor after examining the charred the remains tree, "Just the ability to manipulate energy efficiently, probably the result of a pyschic field in this universe."
"You say the strangest things."
"I do not! You just don't understand them. They make perfect sense!"
"Would you like to see again?"
"Not yet, just give me one second..." And the Doctor rushed back into his TARDIS and out again with yet another tool. This one was roughly the size of several of his hands, and appeared like the steering wheels the dwarves used for their ships. He pressed a few buttons and said, "Ok then, do it again." Illiamen shrugged and said, "Arduna risa." Dew from the leaves rose and collected in one small orb in front of the Doctor. "Interesting. By all means, impossible, but what if..." Then he cried out, "OH! The energy level is so high in certain individuals here that you can manipulate the flow of other energy. If everyone could, then they would cancel each other out and only the strongest ones would be able to continue. So this is magic then."

As they were eating the stew, the doctor put aside his bowl and turned to the TARDIS. "It can go anywhere you know. All of space and time, anywhere you could imagine. And now that I've gotten here... I could probably get back. Would you like to come with me?"
"Anywhere?"
"Anywhere."
"Seriously?"
"Seriously. So what do you think? All of space and time... Every galaxy, every universe to explore... Would you like to come?"
"Yes."

Once they had finished eating, the Doctor put away his tools. "Well that was splendid!"
"Doctor, you saw in the book of prophecy that it was foretold that you would come here, but..."
"But what?"
"But you didn't see the reason, did you? You didn't see what you would do." So Illiamen taught him the history of Du Fyrn Skulblaka, the dragons, the elves mistake, and, among other things, her desire to stop it.
"Well, the connection with you... elves, and your environment, is highly powerful. It is theoretically possible to increase that connection in a certain area, bonding you with the dragons."
"Ok, so... what?"
"I can bond an elf with a dragon. Then, the war might be resolved. Can you get me an egg?"
"Yes."

One Day Later

Another raid was conducted. Normally, they wouldn't raid so early after another, but the Doctor had managed to locate a nest of young dragons, and it had a few eggs inside. Illiamen had reported the nest, making sure she told her superiors about it in a way that made it seem like she had noticed it when singing to a plant by the Menoa tree. The public object of the raid was to herd the young dragons further away from Ellesmera, but the Doctor had told Illiamen to obtain an egg before the dragons could carry them away. Illiamen was in the front line, and the doctor had given her a device to clip over the egg. It would then transport to the Doctor.
The battle-clad troops raced over the hills, ready to ward off the dragons. The first line received a surprise as dragons plummeted from the sky. Half of the eleven troops were obliterated by the fires, but a friend of Illiamen's managed to protect a small group of them using a shield spell. Half of the remaining elves stayed behind to protect the charge and keep these dragons back.
By the time the charge arrived at the dragon's nest, there remained only four-and-twenty members. Eighteen, Illiamen included, headed for the nest itself. The other six were to extend their minds in search for dragons, and warn others in case they found one.
A cry came from below almost at once, as Illiamen and her companions scaled the cliff side. The first three elves to reach the top dodged around the fireball that had been release from the dragons' maw. Swords danced and claws flashed as the younger dragon fell to the ground. The older one destroyed the elves who had reached the top in revenge. The last line of elves swarmed over the rocks as the dragon burnt them all down. Finally, there remained only four elves. Illiamen rushed to the dragon and gorged his wing in half, while the other attacked it's belly. Unable to sustain it's flight, the dragon crashed onto one of the elves, killing him. His sword piercing the dragon's belly. "Go, explore the immediate area and make sure it's safe!" Cried Illiamen. Once the others had gone, she located a white dragon egg amongst a small pile and clipped the device onto it.

It started to glow just as a she heard a growling behind her. She turned around to discover that the younger dragon was still alive, but just barley. It unleashed a torrent of flame just as the device teleported her and the egg away.

The Doctor was waiting for her. A machine of his was hooked to the inside of his TARDIS, to be specific, the heart of the TARDIS. At the very center of the machine was a small cave for the egg. Then, the two appeared, the air sizzling because of the teleport. The egg fell to the ground and the Doctor picked it up and put it in the cave. He immediately started the machine and the machine started to alter the fabric around the egg, making it more friendly to whoever touched the dragon first. There was a thump behind him and the Doctor opened his mout. "I'm sorry. I'm so sorry." He turned around and saw the burned body of Illiamen lying there. He quickly picked her up and deposited her in a pile of blankets he had prepared. "I could have taken you to so many places... The diamond planet of Midnight, the Suvena Falls; greatest in the universe, I could have taken you to the beginning of the universe itself."
"And you still can."
"No." The Doctor left for a moment, then returned with the book of prophecy. He showed her a picture, and she gasped. "W-When?"
"Just after you left... The universe is a very large thing; maybe we'll see each other again." A smile rested upon Illiamen's face. She drew her last breath and said, "Goodbye, Doctor, and thank you for saving us..." Her limp form fell and the Doctor closed her burnt eyes. He turned back to the machine, took out the egg, and threw it down the cliff in rage. The egg just bounced off the rocks unharmed and came to rest in a small meadow. The Doctor stepped into his TARDIS with his machine. The engines revved and a grinding sound came, then it and the TARDIS faded away, then they came again before everything disappeared altogether. Left behind was Illiamen's body, the stew, and an open book with a picture on the page. On the picture was a man dressed in pure black, chained with blueish-green chains, screaming at the sky.

When the Doctor responds "You know when you're a kid? And they tell you that the earth is actually round and and floating in space, and you just don't believe it because everything looks so flat? I can feel it. I can feel the rotation of the earth, us just barely hanging on, and if we let go...", - Quoted from Series (not season) 1, episode 1 "Rose".

The Rigmar is introduced in Eldest and though it used to be used to prepare for war, it is now used by most elves for health and fitness.

A Fairth as explained in Inheritance is a painting/picture made using magic.

PS: In the Ancient Language, Astruator means flavor.