Jo wasn't even sure what had happened. She had felt the pain and the loss of blood and knew that her number was up. The one good thing about it was that she would be able to help Sam and Dean by taking out the hellhounds. She knew that they didn't like the idea -- Dean's face and Sam's eyes had told her all about that. However, she was dying and there was no way they could deny that. When it came right down to it, they couldn't argue much with her decision.
She could and did try to argue with her mom's decision to stay, but short of the boys trying to drag her out of the store, that wasn't going to change.
She watched the guys leave the store and then leaned her head on her mother's shoulder. She didn't know what she was saying since she was already drifting away, but she wasn't afraid.
When she opened her eyes again, she wasn't in the the store. In fact, she was sitting outside, propped against the wall of one of the buildings. She got up, confused because she could feel her legs again and looked down at herself. Her clothes were still ripped and there was so much blood... but she didn't seem to have anything more than some cuts and scrapes.
She stepped out of the shadows of the building trying to figure out just what the hell was going on. This wasn't Carthage or Hell or Heaven, so where was she?
Hearing someone calling, she responded with her own hello, only then worrying about if she had just given away her location to a demon or something.