 " Vatos " is the fourth episode of the first season of the post @-@ apocalyptic horror television series , The Walking Dead . It originally aired on AMC in the United States on November 21 , 2010 . The episode was written by Robert Kirkman and directed by Johan Renck . In the episode , Rick Grimes ( Andrew Lincoln ) , Daryl Dixon ( Norman Reedus ) , Theodore " T @-@ Dog " Douglas ( IronE Singleton ) , and Glenn Rhee ( Steven Yeun ) return to downtown Atlanta in search of Daryl 's brother , Merle . The group are later targeted by a Latino gang , whose leader threatens to kill them if they do not relinquish their weapons . Meanwhile , Lori Grimes ( Sarah Wayne Callies ) and Shane Walsh ( Jon Bernthal ) ' s relationship begins to crumble . 
