It had been a year since the near-apocalypse. One year since Sam had sacrificed himself. In the beginning, Dean had been a wreck. But over time, the loss and anger receded. Not much, but enough to allow him to live normally. They had found a place to call home in a quiet town. Dean worked as a mechanic and Abigail was an athletic trainer in the high school. Dean cleaned the gutters and trudged out in the mornings to fetch the paper. Abigail baked pies and made sure bills were paid on time. They were friendly with neighbors, but generally kept to themselves. They lived normal lives- of course, sleeping with a loaded shotgun within easy reach went without saying. No monsters ever came to town. It seemed the entire country was recovering from the apocalypse scare. Before leaving Bobby's, Baby had been fixed up. Now, she sat in the garage, alone and unused. When home alone, Abigail would sometimes pull the cover off and sit inside with the familiar smell. She might even turn on the engine just to hear Baby's purr. But it was as if Baby was the personification of their hunting experiences, and they were trying to hide that past, from themselves as much as the neighbors.
Moving on went against everything Dean stood for. He could not really be expected to let Sam go without even trying to save him. But he had made a promise and it had been Sam's last request. So he was going to give up on his little brother.
Abigail liked living in one place, being able to go to sleep in the same bed. She liked the consistency. And though she knew it would take time and he would not admit it, Dean liked the consistency, too. She tried to make things easy for him, worked to make their new lives as appealing as possible. They did not have a white picket fence, but it was more or less the idea Dean had always had. Abigail still wore the ring on her hand, but never said anything about it. Neither of them were recovered enough yet. And secretly, she wanted to wait in the ridiculous hope that Sam would be there, too.
So, naturally, it was too good to be true when Sam showed up a year later. Abigail was getting home from work when she heard something in the garage. She expected it to be Dean working on Baby or trying some stupid trick he saw on the internet. After he tried doing the cinnamon challenge and spewed it all across the kitchen, she had told him these challenges needed to be done in his "man cave" in the garage, or outside. She was struck dumb at seeing the familiar figure of Sam. She blinked, opened her mouth, shook her head and blinked again. Dean confirmed that his brother really was back. Sam hugged her back stiffly. But she was too exhilarated to notice.
Sam was back.