He had no destination in mind. He just walked, not really seeing anyone, not sure where he was. It did not matter. He had far to much to think about to be concerned with something as mundane as physical location.
Most of the people here were strange, there was something a little unreal about them, while others were very real. These looked vivid by comparison, like a bright light in a dark room.
As he walked past what turned out to be the hospital he saw one, sitting on the steps. He was drawn to her, amongst all the others passing by she was the only one that could hold his attention, the one one who seemed real. She was one of them.
There was something else too. She had a look about her, disaffected, disconnected. This drew Castiel in it's familiarity. He walked over to her and sat on the steps beside her.