(extended summary!)
NANCY ARGENT always dreamt of having the perfect life. One with no tears, heartbreak or despair. To have someone who loved her and supported her. But of course, in the life of the supernatural where you spent your days killing monsters, befriending angels and making deals with demons... that was never going to happen. So it was no doubt that when she got the chance to get out of that life, she took it.
She took the chance to become an intern at one of the top hospitals in the area; her dream job and accepted an engagement from the stereotypical perfect dream guy. Jordan. He not only was incredibly attractive but also was becoming a lawyer and so between the two they bought a house in California one of Jordan's dream places to live and so when coincidentally she found out that her old childhood friend, Sam Winchester was accepted into Stanford and gotten the chance to start over himself she wasn't surprised that it was easy to keep in touch.
But there was one thing she missed the most about her old life and that was Dean. Dean and her were always connected growing up. As cliché as it sounds, they both had clear feelings for each other but were to afraid to admit it because everyone they loved ended up getting hurt because of what they did. Which is exactly why Nancy never told Jordan about her past life and the monsters that roamed the dark.
But all the changed after Dean and Sam showed up on her doorstep begging her for her help to find their father and she figured that after all John did for her growing up and practically raising her - since her parents both passed when she was younger due to a hunt - she figured the least she could do to repay him for his effort would be to make sure he's still alive. Not to mention, she could almost never turn down the Winchesters because of the hold they have on her humanity so they girl packed up her things for a few nights and took off unaware of the heartbreaking events that would be ready for her to walk in on when she got back.