Hello people. Okay, I know I shouldn't be starting a new story, I already have six on the go and a sequel I'm working on, but this idea has been swimming round in my head all summer ever since I started re-watching supernatural from season one again and just won't let go, so I find that I had to write it.

This is a long introductory chapter before the action as such starts. The bits in italics are writing in the book (that will make sense when you read it hopefully). I hope you like the latest crazy plot my mind has come up with.

Enjoy.

Disclaimer: I don't own Supernatural.

Castiel returned to the bunker despondent, the spell that had cost Charlie her life to translate hadn't worked, the mark of Cain was still upon Dean and now Sam was dead. There was nothing and no one who could bring him back from that death. Not even God himself could resurrect someone killed by Death's scythe.

And then there was Dean, Dean. He didn't even know where Death had put him. No all Death had told him was that he was gone where Castiel would never find him and the angel's job was done. The Winchesters time on earth had come to an end and with it the end of Castiel's guardianship of them.

But it had been a long time since Castiel had thought himself their guardian, he was their friend, their family, and now Dean was out there all alone with the knowledge that he had killed his brother. No Castiel would not let this be the end of their courageous story. Sam and Dean had gone through too much, given up too much for it to end this way. It had been with that in mind that he had taken both the book of the dammed and the codex from Rowena's grasping claws, leaving her to the mercy of her son and returning here. Somewhere in this bunker there must be a way to make it all right once more. There must be some way for Castiel to fix it all.

With that thought Castiel locked away the book of evil and burnt the codex before turning to the pile of books and things belonging to the Winchesters and started the task of putting it all back into its rightful home. Sam and Dean would want it when he found a way to return them, even if it took him centuries to do so. It wasn't like he had anywhere else to spend eternity after all.

It didn't take him centuries in the end, but it did take a few years. Luckily the angels left him alone, Hannah not wanting to fight him, and so he had time to search the bunker methodically and completely, the most unusual thing about that time was his occasional companion.
Crowley turned up at the bunker a few weeks after Castiel had left Rowena in his care. It seemed that his mother was now visiting hell on a more permanent basis than she had before, not that Castiel truly cared about the fate of that woman, he still hadn't forgiven her for equating him to a fish. But it seemed that Crowley was also missing his bestie as he insisted on calling Dean no matter what Castiel said to the contrary, and as such had been searching throughout the universe for him but so far to no avail, though of course the universe was infinite so Crowley didn't truly hold out much hope of stumbling across Dean, but at least it gave him something to do. Life without the Winchesters had become decidedly boring in the mind of the king of hell. It was all so routine, and he had yet to find an adversary who could challenge him, well expect the angel who was obsessed with bringing back the Winchesters at any rate. And as such he visited said angel regularly. Most of the time he was his snarky self, refusing to help Castiel find what he was looking for or just generally getting on the angels nerves, but they formed a strange sort of bond. They had been enemies, they had worked together, they had fought, but they had never really been friends, not that either of them would say that that was what they were now on the pain of death or worse, but they had a sort of tolerance for each other, and they both knew deep down, that their feelings for Dean Winchester connected them in some way that had never been achieved before. Not that that surprised either of them, they both knew not to underestimate the Winchesters after all.

It was on one of these visits that Crowley was sitting at the table with his feet upon the top sipping whiskey that he had had to supply himself, the Winchesters whiskey didn't even qualify for the name in his mind, that Castiel stumbled across a book he had never seen before, though he was sure that he had checked the bookshelf he had found it on thoroughly, but he was not going to question this discovery. The title alone gave him hope.

The Dos and Don'ts of Changing Destiny, Or What the Fates Will Allow

It was a small, leather bound, hand written book that would easily fit into the pocket of his trench coat, it looked, on first inspection, as if it was very old, but once a closer examination was taken Castiel had the suspicion that it was actually very, very new. Though how a new book on destiny would get into the bunker and into his path he had no idea, though he hoped that God might have had a hand in it. He was never sure what his father would and would not do to help or hinder him. He did keep bringing him back to life after all. He had to have some purpose for him and maybe this was it. With that he made his way to the table opening the book as he went the first page made his eyes widen, for it read,

Destiny cannot be changed as is known by all. But humanity was created with free will, as such the choices one makes can change the path being walked. For example The Titanic must sink, but whether a human choses to travel on the ship is there's to make. If the choice is changed the fates will not be able to interfere.

This little book of prophecies (for want of a better word) can give the reader a guide to a time when choices changed the world and destiny was defeated by them. Though whether it will help for the better or worse I cannot tell. All I know is that for the right person, with this as a guide, a different path can be travelled by all.

Good luck. This is all the help I have to give.

Flicking to the next page to find out just what the introduction meant he found another sentence,

Death is not always ordained by fate, it can be a choice (for instance in deciding to make a deal with a demon). And choices as stated, can be changed.

He felt that this just reiterated what had been said in the introduction, but it was obvious that the writer of this book found it important enough to state separately. With that he turned to the next page, the words in front of him made him sit down heavily.

The soul of the righteous man alone is the price for resurrecting his brother, but whether he breaks the first seal is his choice.

Quickly flicking through the book Castiel found more and more statements that referred so obviously to the Winchesters, and some of the later ones to himself and even Crowley. There was no question in his mind that this book had been given to him as a guide to make things right. The only problem being that all the choices and destinies it referred to were in the past and had been done. And he knew from experience you couldn't change the past. It was then that the prophecy on the last page caught his eye.

To change the past the balance must be kept, if good is to return, then evil most do so as well. If the balance is kept, then the fates will be appeased.

With that Castiel sat back in his seat as he thought. The meaning to him was clear, if he was to go to the past and change the Winchesters destiny then he couldn't go alone, he would need to take a demon with him. One particular demon. With that thought he looked up at Crowley sitting across from him and stared.

Crowley had been enjoying his whiskey in peace, he was just about to get to annoying Castiel when he felt the angel's eyes on him.

"What is it Castiel?" he asked wearily he did not trust that look in the angels eyes.

"I need you to come to the past with me and rewrite history." Castiel replied without a flicker of doubt in his voice.

"And why would I want to do that?" Crowley asked raising his eyebrows at such a suggestion.

"Because it would change this present." Castiel stated as if this was obvious.

"Again why would I do that?" Crowley asked because really, he was the king of hell and had no one trying to kill him, yes his life might be boring, but it was still good.

"Because you are not happy." Castiel suggested, Crowley had after all been human once.

"I'm the king of hell Castiel, if I want to be happy I go torture my mother." Crowley replied with a roll of his eyes, did Castiel really think that argument would work on him?

"It would save Dean." Castiel stated, refusing to add the hope into that sentence, he would make sure that Dean was saved this time.

"And why would I want to save Squirrel?" Crowley asked, though he knew that on this Castiel had hit a nerve, he would like very much to save Dean, he had always been a worthy adversary.

"Isn't that why you come here?" Castiel asked confused now. Surely it was.

"No, I come here to annoy you for my own amusement. Though now it seems to be the other way round. So I'm just going to go." Crowley stood to leave pulling his jacket straight as he did so. Though he waited, he was wondering just what Castiel would offer him to agree to his plan.

"If you come you can be the one who holds the contract for the righteous man's soul." Castiel offered in desperation. If this was the only way to save Dean and Sam then he would do it.

"You are giving me Dean's soul?" Crowley asked in disbelief.

"When the time comes and until I rescue him." Castiel corrected not mentioning that he will do everything in his power to make that an if.

"And if I stop you?" Crowley asked, because really, Castiel was offering to give him Dean? What was that about? He thought the whole point was to save Squirrel and Moose.

"Then you will have demon Dean again, and from what I remember you didn't particularly like him the first time round." Castiel stated reminding Crowley of when he had saved his life so that he could stop Dean.

"That was because he was a knight of hell. A normal Dean-mon I could handle." Crowley replied with shrug of his shoulders.

"You really believe you could handle Dean Winchester? I've yet to meet anyone who has managed that." Castiel said with the raise of an eyebrow. Dean was not one to be handled, as the angel had found out himself the first time round.

"You seemed to have managed." Was Crowley response. He quite liked the idea of turning Dean into his pet demon. It would annoy Castiel no end.

"I don't handle Dean, Crowley, I am his friend." Castiel replied with a growl at the king of hell.

"Yeah right, your Squirrel's bestest friend in the whole world. One of these days Castiel you are going to have to admit the truth." Crowley stated smugly.

"What truth?" Castiel asked tilting his head as he didn't understand what Crowley was trying to say, making the king of hell groan at his obliviousness before he spoke.

"I give up. Look Castiel, it doesn't matter if I would be willing to come to the past with you, neither you nor I have the power to get either of us there so how do you plan to make the journey? Because I'm pretty sure that your fluffy winged family sitting up on their clouds won't help."

Castiel sat back at those words because what Crowley was saying was true. But if that was the case, then why would this book be given to him now? Looking down at it he slowly turned it around in his hands studying every inch of it. After all if his suspicion was correct and it was his father who had left this for him, then surely he would have made sure that it would give him a way to take them both back. Suddenly his eye caught something on the back cover and he looked at it closer. Pulling his eyes away and back to Crowley he had a small smile on his face as he spoke. "I know a way." Of course then a frown replaced the smile as the next obstacle confronted him. "But I don't know when to go to."

"Well how are you going to decide that then?" Crowley asked leaning back in his chair once more as if this was an academic conversation, which it was, after all he hadn't agreed to go.

"Do you have a copy of the Winchester Gospels?" Castiel asked sitting upright and leaning on the table. He didn't have the patience to go out and find them.

"The what?" Crowley asked confused by that because… the Winchesters Gospels? Really?

"The supernatural books." Castiel stated as he realised who it was he was talking to.

"Yes. Why?" Crowley asked getting over the stupid name the angels seemed to have given them.

"Because I believe I would like to borrow them." Castiel stated making Crowley roll his eyes at him before he pulled the laptop which was on the table to him and pulled up all the books that where online.

"Ta-da." He said sarcastically as he turned to screen back to the angel who grabbed it and started reading from the beginning, trying to find the right time to go back and change the past.

Crowley knew he should leave, but he didn't. Instead he just watched Castiel pour over the laptop looking for a time to go back to. He really didn't want to have to return to that time. He wasn't going to and that was that. But, (why was there always damn but?) his life had been boring, and well, if he could go back in time with the knowledge he now had, he could easily take over the world. Especially if they were going to a time where the Winchesters where busy worrying about the apocalypse rather than him. Smiling to himself at these thoughts he was pulled from his mind by a sound very unlike anything he had ever heard from the angel across from him, which caused his eyes to widen in alarm.

"Eureka." Castiel shouted having found the time he needed to go back to and what it was he needed to do. "Give me your hand." He demanded turning to Crowley.

"Now why would I do that?" Crowley asked with a raise of his eyebrows.

"Because I need your blood." Castiel said as if it was obvious.

"No."

"Crowley, this is not a game. We are going to go back and save Dean and Sam, do you understand me?" Castiel asked narrowing his eyes at the demon across from him.

"Or what?" Crowley blustered, he really didn't want Castiel to skewer him. Though of course if he did that the angel wouldn't be going anywhere.

"Crowley." Castiel growled in a threatening voice and the king of hell knew he was walking on thin ice right now. Time to concede.

"Fine. But I don't suppose you'll tell me anything else, like how we're getting to the past or when we're going to? You know the useful little things called details?" He asked as he reluctantly held out his hand palm up.

"No." was Castiel's response before he pulled out his blade slashing Crowley's palm and then his own. Then grabbing the book of prophecies, he slammed there two bloody palms down on the cover and concentrated on the time which they needed to travel to. The 4th May 2006.