Prologue

-Dean-

Sam and Dean were having a normal day, or as normal as life gets when you're a hunter. They had just finished exorcising a poltergeist in Cedar Falls, Iowa. Dean's annoying Metallica music was blaring on the stereo. Suddenly Cas appeared out of nowhere in the back seat of the Impala.

"Sam, Dean. I need your help," Cas said in that low voice of his, causing Sam and Dean to just about jump out of their skin.

"Damn it Cas! Stop popping up in my car! Especially when I'm driving!" Dean shouted looking up in the rearview mirror to glare at the angel's reflection.

"My apologies Dean, but this is an emergency." He stared at Dean with his vibrant blue eyes as he spoke. "There is a… situation. We need your help."

His eyes are so gorgeous, Dean thought. Oh God, what the hell am I thinking. Focus Dean! He was pulled from his thoughts when Sam spoke.

"Help with what?" Sam asked the angel.

"Stopping the apocalypse," Castiel said bluntly.

And with those three words, Dean flipped shit. "WHAT?! What is it now? We beat Lucifer and Sammy lost his freaking soul, we managed to get it back only to have to go and kill Eve, and then on top of all of this we ganked the freaking Leviathan and then escaped from purgatory. Couldn't we catch a break just this once?" Dean exclaimed.

"I'm sorry Dean," Cas said, "but this is a matter of grave importance. There are people who need you and Sam to help. At least this time it isn't your own world that is in jeopardy."

Dean was about to start shouting again when Sam cut him off. "Hold up just a minute Cas. What do you mean it's not our world in jeopardy? Explain."

How the hell is Sammy staying so calm?

"Yours' is not the only version of planet Earth that my Father created Sam. Many other universes exist, some of which are very similar to your own and others that are very different. We angels assumed that, since the two of you have already saved this world so many times in the past, it would be easy for you to do so again."

"If you expect us to go running off to save some parallel world we need a little more information than that," Dean snapped bitterly as soon as Cas finished talking.

"There is a prophet in one of these other worlds who saw that, unless the two of you are present when the final battle takes place, the world will fall and Lucifer will claim the earth as his."

"But what makes that world so different that the Sam and Dean over there can't save themselves?" Sam questioned.

"Well," Cas said looking uncomfortable, "first of all the apocalypse starts about 11 years before it did in this world. Sam, you are 15 and Dean, you are 19." Cs stopped for a moment to let that sink in.

"And?" Dean said impatiently. By this time he pulled the Impala over to a small lot along the road.

"Sam, this may come as a bit of a shock but… in that world you and Jess meet for the first time while you are in high school. And Azazel didn't kill her." This statement caused Sam to go wide-eyed in shock but Cas was not done yet. "However, Jess is very different. The Jess in that world is involved with the version of you over there, but…Jess is a 16-year-old male named Jesse."

Wooow. Dean thought as he snickered at Cas's last comment. All of that teasing about me and Cas and Sammy has a boyfriend.

"There is also a version of me there. I have the same vessel but only 10 years younger, and that version of me is in a relationship with you Dean."

Dean paled as Sam attempted to hide his laughter with a cough at the thought of teenage Dean and Cas as a couple.

"And lastly," Cas said, "you are both females."

"WHAT!?" Sam and Dean roared in unison.

"Yes," Cas said calmly. "Samantha Winchester. Boyfriend: Jesse Lee Moore. Dina Winchester. Boyfriend: Castiel, angel of the Lord."

"What the hell Cas! We're chicks!? Why in God's name would you put the fate of the world in the hands of two teenage girls? And why the hell would YOU be dating ME!?" Dean shouted. "Were you trying to end the world?"

"We angels do not decide the course of earthly events Dean," Cas said softly. "We simply ensure that everything on earth goes according to the way God planned them. We ensure that all things go according to His will."

"Wait," Sam said hesitantly, "so how are we supposed to help these people exactly?"

Dean could tell by the way Cas looked that he definitely wouldn't like the answer to Sammy's question.

"Come with me," Cas said. He then reached forward and gently grabbed Sam and Dean's elbows. With a burst of rushing air, the trio disappeared.

"What just happened?" Dean said as he stared at the strangely familiar landscape around them. "What happened to baby? Where did she go?"

"Calm down Dean," Cas said.

Sam and Dean looked behind them and instantly recognized the brown brick building behind them. It was a high school that they had attended for a few weeks when they were younger. Dean had been 19 at the time and Sam had been 15. "Why are we suddenly outside one of our old schools?" Dean asked.

"This," Cas said ominously and, even though Dean was sure he didn't intend to his tone of voice made his next few words sound ridiculously dramatic, "is where the end of the world begins." He paused as he continued, trying to be as clear as he could. "This is where Samantha Winchester unknowingly breaks the final seal holding Lucifer back from the world. This is were she kills Lilith only, in this world she does not yet have access to the powers given to her by Azazel's blood. She does it with a demon knife."