Assorted enemies pressure Rick and the group; the survivors and the prison may reach a breaking point.
Sneak Peak: Inside The Walking Dead 4.05 "Internment"
Vidcap: The Walking Dead 4x04 "Indifference" - Rick decides Carol is a liability and makes the difficult decision to exile her from the prison. (Spoilers)
Official website: http://www.amctv.com/shows/the-walking-dead