I was thinking this would take place when they are in the prison or while they are in Alexandria. This is would be when the group is trying to find a place to settle. Just when it seems things are settling and they are starting to get some pattern of a normal life rumors start flying. Of someone who can walk around the walkers unnoticed. She doesn't speak and usually when people are near she retreats back. Which made his encounter with the woman they had named Ghost somewhat unique. Daryl was out on what was suppose to be a normal supply run when things went bad. Before anything can be processed he is pushed back in a corner his presence hidden by her. For a long few minutes he is eye to eye with her. After that there is something about those ice blue eyes that stick with him. Maybe it was some time that night he decided he would bring her in, if for no other reason then to find out why the walkers seem to ignore her when other would be torn to shreds. This is just the basic idea and there is a lot of wiggle room with this idea. I am very open to talking about and working out the rough parts.