The episode opens with Rick sending his morning radio message to Morgan, recapping what occurred to the camp the previous night and warning him not to come to Atlanta because "it belongs to the dead now". Meanwhile, the survivors of the attack start to clean up, burning the walker bodies and burying the dead from their group. Andrea keeps vigil over the body of her dead sister Amy, and the group worries when it turns out Jim has been bitten.
Daryl is about to use a pickax on Ed's dead body, but Carol stops him and does the deed herself, saying that she should do it because he's her husband. She cracks Ed's skull open with the pickax, and all of her anger against her abusive husband is let loose. Later, Amy reanimates, and Andrea puts a bullet through her sister's skull.
Rick believes that there may be answers at the Centers for Disease Control and suggests the group head there, but Shane disagrees, saying they should head to Fort Benning instead. Both agree that they're vulnerable where they are now. Shane accuses Rick of not being there and protecting the camp. Rick suggests that he knows Shane had accepted Rick's family as his own. Later, in the woods, Shane aims his weapon at an unaware Rick, but Dale interrupts before things escalate.
Shane announces to the group that whatever happens, they should stick together, but the Morales family has decided to break away, taking their chances with relatives in Birmingham. The rest of the group start a caravan towards CDC headquarters. However, Jim is getting sicker and he keeps having visions of walkers. He requests to leave the group, and he's left underneath a tree at the side of the road.
Meanwhile at CDC headquarters a lone scientist, Dr. Edwin Jenner,is still struggling to find a cure for the disease, but he hasn't been successful so far. He still sends out video messages but doubts that anyone is still listening. His latest experiment goes awry when he accidentally destroys his cache of flesh samples. Depressed and thinking that he might be the only man left, he has decided to kill himself.
The caravan arrives outside the compound. Surrounding the building are a lot of corpses, as well as swarms of flies. A stray walker wanders close but is quickly disposed of. There doesn't seem to be anyone around, and the group considers leaving before it gets dark, but Rick resolutely marches to the entrance. Dr. Jennersees him via remote camera, and Rick notices that the camera moved so he begins to demand entrance into the building.
The group is just about to leave when the door to the CDC opens.