“The Walking Dead,” Season 2, Episode 7, “Pretty Much Dead Already,” Glenn reveals to the rest of the group what he knows about the barn filled with walkers. This sparks a series of events that will end in a heart-rending big reveal.
The group is divided over what to do about this. Shane is in favor of going to the barn and wiping out all the Walkers. Rick, ever the diplomat, wants to talk to Hershel about it. Hershel is now adamant about them leaving, which Rick believes will be a death sentence for his pregnant wife.
The revelation also places a strain on Glenn’s and Maggie’s relationship. However, they eventually kiss and make up.
Rick seems to be willing to let Hershel keep his walkers in return for letting them stay. Shane is adamant that the walkers need to be wiped out or they go. Dale, seeing nothing but trouble brewing, tries to hide the guns in the swamp. Shane tracks him down and takes the guns, despite Dale drawing on him. Dale, who still has his memory of the world of before humanity left, will not shoot and Shane knows it.
It also seems that Hershel has set traps for walkers and takes those taken into the barn for safe-keeping. To test Rick’s loyalty, he takes him to collect a pair. This is a dangerous operation to be sure, since they want to do nothing else but eat live humans.
Around the time that Rick and Hershel appear with the walkers, Shane appears with the guns. This sets him off and, with most of the group, he goes over to the barn and opens the doors. As the walkers start to emerged, they shoot them down one by one, including the ones Hershel and Rick had brought.
And now for the big reveal.
One more walker emerges from the barn. It is Sophia, the young girl they have been looking for the past several episodes. She has been in the barn all along, having been trapped and brought there by Otis, who was shot and left for the walkers by Shane. She is now one of the undead walkers, a mindless, horrible thing.
Rick is the one who comes forward and administers the coup de grace. He now realizes that killing walkers is not only necessary, but is an act of mercy for them.