<P> The episode was written by Angela Kang and directed by David Boyd . "Secrets" touches on various themes, including abortion, romance, and confession . In preparation for filming, producers initially converted a vacant building in downtown Sharpsburg, Georgia into a temporary pharmacy in July 2011 . Principal photography for the episode occurred a month later in August . </P> <P> "Secrets" attained mostly positive reception from critics, who praised the character development and the storyline progression . The episode attracted criticism from political commentators, who denounced the show for its misleading perception of emergency contraception . Upon airing, "Secrets" garnered 6.08 million viewers and a 3.1 rating in the 18 - 49 demographic, according to Nielsen ratings . It became the second highest - rated cable program of the day, as well as the fourth most - viewed cable program of the week . </P> <P> After he inadvertently discovers the presence of walkers in the Greene barn, Maggie (Lauren Cohan) begs Glenn (Steven Yeun) to keep it a secret . Dale (Jeffrey DeMunn) quickly notices Glenn's nervousness, and when he talks privately to Glenn, Glenn blurts out about the walkers as well as his knowledge that Lori Grimes (Sarah Wayne Callies) is pregnant . Dale confronts Hershel (Scott Wilson) about the walkers . Hershel believes they are still people, including his wife and stepson, and can be cured, and refuses to kill them after Dale explains the danger . Meanwhile, Rick (Andrew Lincoln) and Lori argue on what to do with Hershel's demand to leave the farm, now that Carl (Chandler Riggs) is healed . </P> <P> Rick, Shane and T - Dog (IronE Singleton) give gun training to Jimmy, Carl (Chandler Riggs) and the women on the farm . Shane (Jon Bernthal) takes Andrea (Laurie Holden) aside to give her advanced training after seeing how good she is with a weapon, but she is unable to hit a moving target . Shane tries to encourage her to remember her dead sister, Amy, but this only causes Andrea to storm away . </P>

Why is hershel keeping walkers in the barn