AMC has released the first promo and clips for “The Walking Dead” episode 4.15, airing on Sunday, March 23 and titled “Us.” You can watch the videos below along with two behind-the-scenes clips from Sunday’s episode, “The Grove,” as well as a most talked about scene. “Us” is described as follows: “Survivors rely on brutality and faith.” What did you think about tonight’s episode, “The Grove”? Let us know in the comments below!